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Deep-sea ophiuroids from western Mexico have been documented since 1899, but mostly by non-Mexican expeditions. TALUD is a Mexican project designed to study the deep-sea fauna from Mexico. As part of it, the present contribution provides for the first time detailed information about the taxonomy and distribution, as well as images, of deep-sea ophiuroids from western Mexico, representing a useful taxonomic identification tool for Ophiuroidea from the eastern Pacific. A total of 38 species of ophiuroid (35 identified at species level, one at genus level, and two as confer) were collected from 83 stations located at 123‒2,309 m depth. At a regional scale, several new species records are presented: six for western Baja California, five for western Baja California Sur, two for the Gulf of California, four for Jalisco, 14 for Colima, and five for Guerrero. Geographic (six) and bathymetric (seven) distribution ranges of species are extended. An updated list of deep-sea ophiuroids (61 species) from western Mexico is provided together with an identification key to species collected during this survey. In addition, nine records of deep-sea ophiuroids for the Mexican Pacific are unproven, doubtful or invalid. We corroborated the presence of Ophiacantha eurypoma and Ophiacantha pacifica in the study area and added Amphiura gymnogastra as the first record for Mexico. We propose to transfer Ophiacantha phragma to Ophiolimna on account of it having both granules and spines on the dorsal disc and striated arm plates. TALUD cruises collected 57 % of the total deep-sea species known to occur off Mexico, making it the most important survey of deep-sea Ophiuroidea carried out in western Mexico to date.

Asteronyx loveni Müller & Troschel, 1842 Figs 2, 3A–B, 4A, D–E Asteronyx loveni Müller & Troschel, 1842: 119, pl. X figs 3–5. Ophiuropsis lymani Studer, 1884: 55, pl. V figs 12a–d. Asteronyx locardi Koehler, 1895: 470–471, fig. 10 Asteronyx loveni – Clark 1923: 314–315. — Mortensen 1927: 158–160, fig. 90 — Paterson, 1985: 13–15, fig. 15. Asteronyx locardi – Koehler 1896: 88–89, pl. 3 fig. 25. Material examined MAURITANIA • 1 spec., 25.22 mm dd; 19°34′14′′– 19°31′34′′ N, 17°31′44′′– 17°30′21′′ W; depth 1689– 1628 m; 23 Nov. 2007; Maurit-1107 exped.; stn MU22; Maurit-1107-04528; LZM-UV • 12 specs, 6.08–21.71 mm dd; 19°25′29″– 19°22′44″ N, 17°33′17″– 17°32′11″ W; depth 1778–1811 m; 26 Nov. 2007; Maurit-1107 exped.; stn MU31; Maurit-1107-05231; LZM-UV • 10 specs, 6.83–19.28 mm dd; 19°55′41″– 19°53′05″ N, 18°01′07″– 18°02′01″ W; depth 1808–1862 m; 21 Nov. 2008; Maurit-0811 exped.;stn MU92; Maurit-0811-03931; LZM-UV • 4 specs, 64.90– 22.98 mm dd; 19°51′02″– 19°49′33″ N, 17°55′33″– 17°53′00″ W; depth 1740–1769 m; 21 Nov. 2008; Maurit-0811 exped.; stn MU93; Maurit-0811-03725; LZM-UV • 2 specs, 9.60–12.56 mm dd; 19°35′15″– 19°32′43″ N, 17°35′13″– 17°33′37″ W; depth 1720–1734 m; 21 Nov. 2008; Maurit-0811 exped.; stn MU94; Maurit-0811-03928; LZM-UV • 1 spec., 11.07 mm dd; 19°59′28″– 19°59′01″ N, 17°57′28″– 17°59′07″ W; depth 1746–1749 m; 22 Nov. 2009; Maurit-0911 exped.; stn MU193; Maurit-0911-03154; LZM-UV • 1 spec., 25.74 mm dd; 16°08′44″– 16°11′14″ N, 17°10′08″– 17°08′40″ W; depth 1595 m; 6 Dec. 2010; Maurit-1011 exped.; stn MU274; Maurit-1011-02982; LZM-UV. WESTERN SAHARA • 1 spec., 11.01 mm dd; 21°33′13″– 21°36′08″ N, 18°07′26″– 18°07′09″ W; depth 1860– 1820 m; 17 Nov. 2006; Maroc-0611 exped.; stn MO198; Maroc-0611-16135; LZM-UV • 1 spec., 5.81 mm dd; 22°59′13″– 22°56′19″ N, 17°37′30″– 17°38′12″ W; depth 1562–1577 m; 26 Nov. 2006; Maroc-0611 exped.; stn MO230; Maroc-0611-16155; LZM-UV. GUINEA BISSAU • 2 specs, 13.24–18.81 mm dd; 10°01′18″– 10°00′24″ N, 17°24′56″– 17°25′05″ W; depth 902–908 m; 29 Oct. 2008; Bissau-0810 exp.; stn BS166; Bissau-0811-06529; LZM-UV. Distribution Asteronyx loveni Müller & Troschel, 1842 is a circumglobal species, widely distributed across the three major oceans (Indian, Pacific and Atlantic). In the Atlantic Ocean, it has been recorded on both sides: in the West Atlantic, from North USA to West Indies (Hernández-Herrejón et al. 2008), and in the East Atlantic, from Norway (Döderlein 1911) to South Africa (Mortensen 1933). It also has a wide bathymetric distribution, ranging from 100 to 4721 m (Smirnov et al. 2014). We collected the species at eleven stations from Western Sahara, Mauritania and Guinea-Bissau waters, between 902 and 1862 m. Remarks This is a deep-sea-water species generally associated with gorgonians and pennatularians (Mortensen 1927). Our specimens were always associated with pennatularians Distichoptilum gracile Verrill, 1882 and Anthoptilum murrayi Kölliker, 1880. Living colour of the species is cream or pinkish orange, more intense in the central part of the disc. The innermost arm spine much larger than the other spines and a hooked arm spine at the tip of the arm are the most distinctive characteristic for this species., Published as part of Calero, Belén & Ramil, Fran, 2023, Euryalida (Echinodermata, Ophiuroidea) from Northwest Africa, pp. 46-75 in European Journal of Taxonomy 870 on pages 51-53, DOI: 10.5852/ejt.2023.870.2117, http://zenodo.org/record/7938618, {"references":["Muller J. & Troschel F. H. 1842. System der Asteriden. F. Vieweg und Sohn, Braunschweig. https: // doi. org / 10.5962 / bhl. title. 11715","Studer T. 1884. Verzeichnis der wahrend der Reise S. M. S. \" Gazelle \" um die Erde, 1874 - 76 gesammelten Asteriden und Euryaliden. Abhandlungen der Preussischen Akademie der Wissenschaften: 1 - 64.","Koehler R. 1895. Draguage profonds executes a bord du ' Caudan' dans le Golfe de Gascogne. Rapport preliminaire sur les Echinodermes. Revue Biologique du Nord de la France VII: 439 - 506.","Clark H. L. 1923. The Echinoderm fauna of South Africa. Annals of The South African Museum XIII: 221 - 432.","Mortensen Th. 1927. Handbook of the Echinoderms of the British Isles. Oxford University Press, Rotterdam. https: // doi. org / 10.5962 / bhl. title. 6841","Paterson G. L. J. 1985. The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) 49 (1): 1 - 162.","Koehler R. 1896. Resultats scientifiques de la campagne du Caudan dans le Golfe de Gascogne. Echinodermes. Annales de l'Universite de Lyon 26: 33 - 122. https: // doi. org / 10.5962 / bhl. title. 65730","Hernandez-Herrejon L. A., Solis-Marin F. A. & Laguarda-Figueras A. 2008. Ofiuroideos (Echinodermata: Ophiuroidea) de las aguas mexicanas del golfo de Mexico. Revista De Biologia Tropical 56 (3): 83 - 167.","Doderlein L. 1911. Uber japanische und andere Euryalae. KB Akademie der Wissenschaften, Munich. https: // doi. org / 10.5962 / bhl. title. 16334","Mortensen Th. 1933. Papers from Dr. Th. Mortensen's Pacific Expedition 1914 - 16. LXV. Echinoderms of South Africa (Asteroidea and Ophiuroidea). Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i Kobenhavn: 93: 215 - 400.","Smirnov I. S., Piepenburg D., Ahearn C. & Juterzenka K. V. 2014. Deep-sea fauna of European seas: An annotated species check-list of benthic invertebrates living deeper than 2000 m in the seas bordering Europe. Ophiuroidea. Invertebrate Zoology 11 (1): 192 - 209."]}

From 2004 to 2012, ten multidisciplinary oceanographic surveys were conducted along the coast of Northwest Africa, between the Strait of Gibraltar and the northern border of Sierra Leone. A total of five species of Euryalida Lamarck, 1816 belonging to three families were captured at 29 of the 1298 stations sampled in the area. Among them, Astrodendrum juancarlosi sp. nov. is described and figured in this paper. Ophiocreas oedipus Lyman, 1879 is recorded for the first time on West African continental margin and Gorgonocephalus pustulatum (H.L. Clark, 1916), an Indo-Pacific species only known from South African coast in the Atlantic, is reported off Guinea-Bissau, greatly extending to the North its Atlantic distribution. In addition, Asteroschema inornatum Koehler, 1906, a northeast Atlantic species, is recorded for the first time in African waters, off Western Sahara, extending its range of distribution to the south. Our data also extend the bathymetric distribution of A. inornatum to shallower waters and of G. pustulatum to deeper waters. The association of some euryalids with certain species of pennatulaceans and gorgonians is also described.

Astrodendrum juancarlosi sp. nov. urn:lsid:zoobank.org:act: ECD0622E-6FAF-4C72-B102-F1B94D8ECBFB Figs 3E–F, 7–9 Diagnosis Species with small granule-like external ossicles, ending in a crystalline point, covering the dorsal and lateral interradial areas of the disc. Ventral disc areas and arms covered by domed granule-like external ossicles without any crystalline point. Two or three terminal projections on each arm spine; one secondary teeth on each valve. Etymology The specific epithet ‘ juancarlosi ’ was chosen as a tribute to Mr Juan Carlos Calero, father of the first author. Material examined Holotype GUINEA BISSAU • 2 specs, 40.43–56.81 mm dd; 10°18′55″ N, 16°25′07″ W; depth 79 m; 4 Nov. 2008; Bissau-0810 exped.; stn BS200; Bissau-0810-06403; MNCN 29.02/1534. Paratypes GUINEA BISSAU • 2 specs, 28.20–51.16 mm dd; 11°08′07″– 11°09′33″ N, 17°15′20″– 17°15′44″ W; depth 109 m; 29 Oct. 2011; CCLME-1110 exped.; CCLME-1110 exped.; stn BT53; MHN USC-10132 -1 and 2 • 1 spec., 40.43 mm dd; 10°18′55″ N, 16°25′07″ W; depth 79 m; 4 Nov. 2008; Bissau-0810 exped.; Bissau-0810 exped.; stn BS200; MNCN 29.02/1535. WESTERN SAHARA • 1 spec., 44.62 mm dd; 26°26′23″– 26°25′06″ N, 14°25′30″– 14°26′23″ W; depth 67– 58 m; 29 Nov. 2011; CCLME-1110 exped.; CCLME-1110 exped.; stn BT215; CFM-IEOMA-7776. • 1 spec., 46.70 mm dd; 14°57′00″– 14°58′09″ N, 17°39′08″– 17°38′13″ W; depth 797 m; 25 May 2012; CCLME-1205 exped.; CCLME-1205 exped.; stn BT368; CCLME-1205-03248; LZM-UV. Additional material GUINEA BISSAU • 1 spec., 10.07 mm dd; 11°05′09″– 17°03′15″ N, 11°04′15″– 17°03′10″ W; depth 46–47 m; 26 Oct. 2008; Bissau-0810 exped.; stn BS151; Bissau-0810-06146; LZM-UV. Description (holotype) DISC. Five-lobed in shape, slightly excavated inter-radially (Fig. 8A), with no peripheral calcareous plates on rim. Radial shields tumid, long (almost raising the centre of disc) and narrow, which is deeply sunken (Fig. 8C). Radial shields completely concealed by external ossicles, bar-shaped, as wide proximally as distally, but more separated distally, converging towards centre of disc. Distally, radial shields end on enlarged, slightly concave and oval-shaped plate covered by minute granules (Fig. 8C–D). Dorsal disc covered by small granule-like external ossicles (Fig. 8A, C–D), each one ending in terminal crystalline point. At edge of disc, ossicles more densely packed and without crystalline point (Fig. 8C), and bigger in size between radial shields (Fig. 8C–D). Ossicles concealing radial shields similar to those from dorsal disc but more densely packed.Ventral inter-radial areas densely covered by mosaic of small irregular flat plates with granule-like external ossicles without terminal point. Oral shield, adoral shield, oral plates, along edge of mouth frame and ventral arm plates more densely covered by similar external ossicles. Mouth frame sunken (Fig. 8E). Interradial surface of lateral disc covered by external ossicles similar but smaller than those covering dorsal disc. Two large genital slits on each interradius running almost vertically along first five or six brachial segments after first fork (Fig. 8F). Conical external ossicles with terminal crystalline point more developed on adradial edge of genital slits. One oval-shaped and well-developed madreporite located just outside mouth frame (Fig. 8E). Both, tooth and oral papillae spiniform, especially larger apical ones. Mouth and infradental papillae form continuous series along mouth frame (Fig. 8E). Teeth varying in position and size, being irregular in outline and more or less irregularly disposed. ARMS. Arms branching, with first fork before disc margin and second one located at margin. Nevertheless, in smaller specimens (juvenile), first fork located on margin of disc. Arms tapering gradually towards tips, completely covered, both, dorsally and ventrally, by domed granule-like external ossicles (Fig. 9A); these granules somewhat bigger than disc ones and without any crystalline point. Dorsal side of arms carry pedicellarial bands along whole arms. Valves with one secondary tooth downwardly curved (Fig. 9C). Some sunken transverse furrow between segments, giving arms an annulated appearance. Indication observed of median furrow along arm (Fig. 8G). Ventral side of arms with noticeable transverse naked furrows between segments until second fork; afterwards, furrows become smaller, disappearing after third fork. First two pores without arm spine. Arm spines beginning at third pair of pores with only one small spine at third and fourth pair of pores, two arm spines (sometimes one) afterwards and three arm spines (sometimes two) after second fork. Arm spines short and wide, ending in two or three hyaline points (Fig. 9F). Vertebrae streptospondylous (Fig. 9G–K). COLOUR. Living specimens showing varying colours, from creamish-pink to dark orange and brown to gray (Fig. 3E–F) with clear ventral part; preserved specimens are white. OSSICLE MORPHOLOGY. External ossicles on dorsal surface of disc, including radial shields, are granule-shaped and ending in a crystalline point (Fig. 9A). Baseplates oval-shaped with three to five tubercleshaped articulations for pedicellarial (Fig. 9D). External ossicles on baseplates granule-like shaped, approximately 200 µm in length and 100 µm in height (Fig. 9B). Valves with single inner tooth downwardly directed, and reticular structure (Fig. 9C). Lateral arm plates long, bar-like, with tuberculous stereom, spines placed in external lobe of plate (Fig. 9E). Arm spines ovoid-shaped with two or three small projections, not transforming into hook-shaped spines on distal portion (Fig. 9F). Vertebrae with hourglass-shaped streptospondylous articulations (Fig. 9G–K). Branching vertebra wider and with two surfaces for articulation. Distribution This species has been recorded in the Northwest African coast, from the Western Sahara to Guinea-Bissau waters. Its bathymetric distribution ranges between 47 and 797 m. Remarks The genus Astrodendrum was established by Döderlein (1911) for Gornocephalus sagaminus Döderlein, 1902. He realised that all species that belong to Gorgonocephalus Leach 1815 are characterised by the presence of a well-developed belt of calcareous plates at the margins of the disc. However, species of Astrodendrum have no ring of calcareous plates at the rim. Additionally, the arm spines appear before the first fork, as in Gorgonocephalus; however, in Astrodendrum Döderlein, 1911, these arm spines are much smaller, hardly reaching ⅓ of the segment length, and their number is reduced: with three (or rarely four) on each side. Taxonomic studies dealing with this genus are scarce, and we have only found a revision of the genus recently published by Okanishi & Fujita (2018). According to these authors, the genus is characterised by having five branching arms, with less than six segments before the first fork; lack of calcareous plates on the edge of the disc margin; variously shaped external ossicles or no ossicles on the disc; a madreporite placed on the innermost part of the interradial lateral disc; and valves from the dorsal arms with one secondary tooth. Currently, only six species have been assigned to this genus. Among them, only Astrodendrum capense (Mortensen, 1933), described from Durban, South Africa (Mortensen 1933; Clark & Courtman-Stock 1976), has been found in the Atlantic Ocean – Namibia (Alva & Vadon 1989). Astrodendrum elingamita Baker, 1974 has been reported in New Zealand and Philippines (Baker 1974; Okanishi & Fujita 2018); Astrodendrum galapagense A.H. Clark, 1916 from Galapagos Islands; Astrodendrum laevigatum (Koehler, 1897) from Colombo (Sri Lanka); and Astrodendrum sagaminum (Döderlein, 1902) from Japan, East China Sea and Sri Lanka (Döderlein 1902, 1911; Clark 1911; Bomford 1913; Matsumoto 1917; Irimura & Kubodera 1998); and the recently described Astrodendrum spinulosum Okanashi & Fujita, 2018 also from Japan. In addition to the shape, size and arrangement of external ossicles – widely used as an important specific taxonomic character (Baker 1974, 1980; McKnight 2000) – Okanishi and Fujita (2018) included the possibility of the lack of external ossicles (as in the case of A. laevigatum), and they also proposed three new taxonomic characters to distinguish species of Astrodendrum: • absence/ presence of bulges on lateral ridges of proximal portion of arm • number of terminal projections of arm spines on proximal portion of arm • number of secondary teeth of hook-shaped arm spines on distal portion of the arm The main morphological features of all known species of Astrodendrum, including A. juancarlosi sp. nov., are summarized in Table 2. Astrodendrum spinulosum differs from the rest of species by the presence of bulges on lateral ridges of proximal portion of the arm. The new species here described, also differs from A. spinulosum by the number of terminal projections of arm spines on the proximal portion of the arm (three in the case of the new species and one in A. spinulosum). In addition, A. spinulosun has cone-shaped external ossicles, while A. juancarlosi sp. nov. has granule like ossicles ending in a crystalline point at the dorsal surface of the disc. Astrodendrum juancarlosi sp. nov. is more similar to A. elingamita in the shape of the ventral coverage and the lack of a scale in the first tentacle pore. Nevertheless, A. elingamita has the first fork in the margin of the disc, while it is located before the margin in our species. The polygonal plates of the ventral covering are closer in the A. elingamita than in our specimen. Our specimens also differ from A. elingamita by having one type of dome-shaped granules with 1–2 hyaline terminal points rather than two smooth types. Astrodendrum sagaminum differs from Astrodendrum juancarlosi sp. nov. in also having two types of granules and naked arms and ventral disk. Astrodendrum capense has several medium-sized conical tubercles along the radial shields; it also has some smaller conical tubercles along the inter-radial disc margin, both ending in small thorns. Moreover, the disc is closely covered with minute and smooth plates. Astrodendrum galapagense has a dorsal coarse armament on the disc and arms. The external ossicles on the aboral disc are plate-shaped at periphery and conical at center, both slightly in contact, while on the oral surface has a few small widely scattered granules, except in the ventral interbrachial areas. Astrodendrum laevigatum is covered by a thin, transparent, soft and perfectly smooth tegument without any granules or spines. According to the description of this species in the literature, there are some doubts about the inclusion of this species in the genus Astrodendrum. We consider necessary to review the type material before we can reach a conclusion on this issue. Therefore, in this paper we follow Okanishi & Fujita (2018) and keep the species within the genus Astrodendrum. Finally, our specimen has marked rectangular furrows that are absent in the rest of the species of Astrodendrum. Even though Mortensen (1933) described the underside of the arms of A. capense as flat and without any grooves, he pointed out that this “may be an indication of a transverse furrow between the segments from the first forking onwards” (Mortensen 1933: 286). See Table 2 for comparison of main morphological characteristics among species., Published as part of Calero, Belén & Ramil, Fran, 2023, Euryalida (Echinodermata, Ophiuroidea) from Northwest Africa, pp. 46-75 in European Journal of Taxonomy 870 on pages 59-67, DOI: 10.5852/ejt.2023.870.2117, http://zenodo.org/record/7938618, {"references":["Doderlein L. 1911. Uber japanische und andere Euryalae. KB Akademie der Wissenschaften, Munich. https: // doi. org / 10.5962 / bhl. title. 16334","Doderlein L. 1902. Japanische Euryaliden. Zoologischer Anzeiger 25 (659 - 684): 320 - 326.","Okanishi M. & Fujita T. 2018. A taxonomic review of the genus Astrodendrum (Echinodermata, Ophiuroidea, Euryalida, Gorgonocephalidae) with description of a new species from Japan. Zootaxa 4392 (2): 289 - 310. https: // doi. org / 10.11646 / zootaxa. 4392.2.4","Mortensen Th. 1933. Papers from Dr. Th. Mortensen's Pacific Expedition 1914 - 16. LXV. Echinoderms of South Africa (Asteroidea and Ophiuroidea). Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i Kobenhavn: 93: 215 - 400.","Clark A. M. & Courtman-Stock J. 1976. The Echinoderms of Southern Africa. Trustees of the British Museum (Natural History), London.","Alva V. & Vadon C. 1989. Ophiuroids from the western coast of Africa (Namibia and Guinea-Bissau). Scientia Marina 53 (4): 827 - 845.","Baker A. N. 1974. New species of brittle-stars from New Zealand (Echinodermata: Ophiiuroidea). Records of the Dominion Museum 8 (15): 247 - 266.","Clark H. L. 1916. Report on the Sea-Lilies, Starfishes, Brittle-Stars and Sea-Urchins obtained by the F. I. S. ' Endeavour' on the coast of Queensland, New South Wales, Tasmania, Victoria, South Australia, and Western Australia. Biological results of the fishing experiments carried on by the \" Endeavour \" 4 (1). Minister for Trade and Customs, Sydney. hhtps: // doi. org / 10.5962 / bhl. title. 13854","Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. Bulletin of the United States National Museum (75): 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Bomford T. L. 1913. A note on certain ophiiuroids in the Indian Museum. Records of the Indian Museum 9 (4): 219 - 225.","Matsumoto H. 1917. A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo, Japan XXXVIII (2): 1 - 407.","Irimura S. & Kubodera T. 1998. Ophiuroidea in the East China Sea. Memoirs of the National Science Museum, Tokyo 31: 135 - 143.","Baker A. N. 1980. Euryalinid Ophiuroidea (echinodermata) from Australia, New- Zealand, and the Southwest Pacific-Ocean. New Zealand Journal of Zoology 7 (1): 11 - 83. https: // doi. org / 10.1080 / 03014223.1980.10423763","McKnight D. G. 2000. The marine fauna of New Zealand: Basket-stars and Snake-stars (Echinodermata: Ophiuroidea: Euryalinida). National Institute of Water and Atmospheric Research, Wellington, New Zealand."]}

Okanishi, Masanori, Dan, Ichinosuke, Hirabayashi, Isao (2023): The First Record of Ophioteichus multispinum (Echinodermata: Ophiuroidea) from Japan, with Notes on Its Ossicle Description and Ecology. Species Diversity 28 (1): 107-116, DOI: 10.12782/specdiv.28.107, URL: http://dx.doi.org/10.12782/specdiv.28.107

Ophiochiton cf. fastigatus Lyman, 1878 Fig. 13A‒F Material examined. Six individuals at four stations. TALUD V, Sta. 19, 2 ind. (ICML-EMU-11176). TALUD XII, Sta. 30, 2 ind. (ICML-EMU-11177). TALUD XVIB, Sta. 5, 1 ind. (ICML-EMU-11677-A); Sta. 28, 1 ind. (ICML-EMU-11677-B). Comparative material. Ophiochiton fastigatus Lyman, 1878, syntype, 1 ind.: MCZ OPH- 1111. Ophiochiton carinatus Lu ̈tken & Mortensen, 1899 (junior synonym of O. fastigatus), syntypes, 2 ind.: MCZ OPH- 1649, USNM 19554 (Supplementary file 2). Description (ICML-EMU-11176). DD = 24 mm. Disc with constricted shape; a preservation artifact. Dorsal disc covered by fine scales, larger scales in disc margin and around RS. Primary plates rounded, very conspicuous, separated from each other by disc scales. RS triangular with rounded edges, separated by numerous scales (Fig. 13A). Ventral interradii covered by imbricated scales (Fig. 13B). OSh broader than long, triangular with rounded edges. Madreporite circular, larger than Osh. AdSh longer than broad, slender, distally triangular and wider, meeting in front of Osh. Jaws bearing 6‒7 papillae at each side, distalmost lanceolate and the largest, apical elongated. vT very pointed (Fig. 13C). Arms fragile. DAP broader than long, trapezoidal, contiguous (Fig. 13D). VAP broader than long, hexagonal, contiguous. DAP and VAP with a longitudinal middle keel along the arm. LAP with three ArSp, very elongated (approximately two arm segments in length), dorsalmost the longest. Tentacle pores with two TSc, adradial slender and elongated, abradial larger, rounded, flat (Fig. 13E). Color pattern in dorsal and ventral side light brown (ethanol preservation) (Fig. 13A‒F). Habitat and distribution. The material examined was collected off western Baja California, in the south of the Gulf of California, and off Jalisco; 772‒ 1,532 m depth. Remarks. The type material of Ophiochiton fastigatus from Japan (MCZ OPH-1111, DD = 15 mm) varied morphologically from the type material of Ophiochiton carinatus (MCZ OPH-1649, DD = 12 mm) in the following characters: RS size, length of adradial tentacle scale, shape of oral shields, shape and number of the oral papillae. The TALUD specimens are morphologically more similar to the type specimens of O. carinatus examined during this study (USNM 19554, DD = 23 mm), but they differ from the latter in the overall shape of the jaw. A thorough morphological examination and a molecular analysis are needed in order to determine if the observed morphological differences are linked to geographic or size variations or if they correspond to different species. Hendler (2018) mentioned that some members of the family Ophionereididae present five oral papillae at each side of the jaw (one LyOs, one AdShSp, one 2AdShSp, one BSc, and one IPa). However, all the specimens of Ophiochiton (type material and TALUD specimens) examined during this study showed 5‒7 oral papillae at each side of the jaw, thus suggesting that one or two papillae have not been accounted for and still lack a proper study. Therefore, more studies on the Ophionereididae jaw´s morphology are needed to understand the homology of these structures., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 45, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Hendler, G. (2018) Armed to the teeth: a new paradigm for the buccal skeleton of brittle stars (Echinodermata: Ophiuroidea). Contribution in Science, 526, 189 - 311. https: // doi. org / 10.5962 / p. 324539"]}

Ophiocten hastatum Lyman, 1878 Fig. 5A‒F Ophiocten hastatum Lyman, 1878: 103, pl. 5, figs. 133‒134.— Koehler 1922: 388‒389.— Paterson et al. 1982: 117‒119, fig. 5.— Martynov & Litvinova 2008: 83, fig. 3c.— Lambert & Boutillier 2011: 47, fig. 33. Ophiocten pacificum Lütken & Mortensen, 1899: 131‒132, pl. 3, figs. 5‒7.— H.L. Clark 1911: 96‒97; 1913: 211.— Kyte 1969a: 1738. Ophiocten longispinum Koehler, 1896: 204‒205. Ophiocten latens Koehler, 1906: 7‒8, pl. 1, figs. 9‒10. Ophiocten australis Baker, 1979: 26‒28, fig. 3a‒c. See Paterson et al. (1982) for other synonymous records. Material examined. 243 individuals at seven stations. TALUD XII, Sta. 27, 2 ind. (ICML-EMU-13002). TALUD XVIB, Sta. 1, 3 ind. (ICML-EMU-11117); Sta. 16, 2 ind. (ICML-EMU-11118-A); Sta. 19, 5 ind. (ICML-EMU-11118-B); Sta. 22, 22 ind. (ICML-EMU-11119) and 1 ind. (ICML-EMU-11680-B); Sta. 26, 90 ind. (ICML-EMU-11120); Sta. 27, 79 ind. (ICML-EMU-11121), 32 ind. (ICML-EMU-11122), and 7 ind. (ICML-EMU-11680-A). Comparative material. Ophiocten hastatum Lyman, 1878, syntypes, 4 ind.: MCZ OPH- 765, MNHN-IE-2013- 10285. Ophiocten pacificum Lu ̈tken & Mortensen, 1899, syntypes, 28 ind.: MCZ OPH- 767, MCZ OPH- 1019, USNM 19484, USNM 19485, USNM 19487, USNM 19488, NHMD 232, NHMD 396 (Supplementary file 2). Description (ICML-EMU-11120). DD = 16 mm. Disc rounded. Dorsal disc covered by irregular and imbricated scales, largest surrounding the disc. Primary plates rounded, conspicuous, separated from each other. RS longer than broad, triangular, separated by numerous scales. Ventral interradii covered by imbricated scales, smaller than dorsal scales (Fig. 5A). Genital slits covering the whole interradius. Genital slits with minute, pointed genital papillae restricted distally, projecting dorsally and forming arm combs with small and slender papillae (Fig. 5B). OSh slightly broader than long, pentagonal. Madreporite not evident. AdSh longer than broad, elongated, slender, almost meeting or meeting in front of OSh. Jaws bearing four papillae at each side; BSc rectangular, very elongated; IPa rectangular, elongated; 2IPa oval; TPa pointed. vT pointed, larger than oral papillae. AdShSp oval, separated by a diastema (Fig. 5C). Arms slender. DAP broader than long, trapezoidal, meeting. First 4‒6 DAP with minute, pointed spines distally (Fig. 5D). VAP broader than long, almost hemispherical with a convex distal edge, obtuse angle proximally; widely separating and decreasing in size distally. LAP with three ArSp, pointed; dorsalmost the longest (one arm segment in length). First tentacle pore with 1‒2 oval TSc; subsequent tentacle pores with one lanceolate TSc (Fig. 5E). Color pattern beige-whitish (Fig. 5A‒F). Primary plates, some scales in dorsal disc, and DAP with light brown tint (ethanol preservation) (Fig. A, D). Habitat and distribution. Atlantic and Pacific Oceans. In the eastern Pacific in California, USA, Mexico, Costa Rica, Panama, Colombia, Ecuador, and off the Galapagos Islands (Paterson et al. 1982; Solís-Marín et al. 2013); 824‒ 4,700 m depth, muddy substrate (Lütken & Mortensen 1899; Maluf 1988). The material examined was collected off western Baja California and off Colima; 982‒ 2,054 m depth. Remarks. The morphology of the TALUD specimens examined herein corresponded with that of the type material of Ophiocten pacificum, which showed differences with the examined type material of Ophiocten hastatum in the size and the shape of the radial shields and the oral papillae shape. Ophiocten hastatum has been recorded as a widespread species across all major oceans (O’Hara & Thuy 2022); however, this taxon has been considered a species complex by Christodoulou et al. (2019). Due to the above, we propose conducting further analysis to determine whether O. hastatum and O. pacificum (as well as the other synonymous records of O. hastatum) belong to the same species. In Mexico, O. hastatum has only been reported from off western Baja California and Baja California Sur (Granja-Fernández et al. 2015). The finding of this species off Colima increases the distribution range of this species in western Mexico. In the eastern tropical Pacific, the genus Ophiocten is only recorded by this species., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 24-25, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Paterson, G. L. J., Tyler, P. A. & Gage, J. D. (1982) The taxonomy and zoogeography of the genus Ophiocten (Echinodermata: Ophiuroidea) in the north Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 43 (3), 109 - 128.","Martynov, A. V. & Litvinova, N. M. (2008) Deep-water Ophiuroidea of the northern Atlantic with descriptions of three new species and taxonomic remarks on certain genera and species. Marine Biology Research, 4 (1 - 2), 76 - 111. https: // doi. org / 10.1080 / 17451000701840066","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Koehler, R. (1896) Note preliminaire sur les Ophiures des premieres campagnes de la \" Princesse Alice \". Memoires de la Societe Zoologique de France, 9, 241 - 253.","Koehler, R. (1906) Description des Ophiures nouvelles recueillies par le \" Travailleur \" et le \" Talisman \" pendant les campagnes de 1880, 1881, 1882 et 1883. Memoires de la Societe zoologique de France, 19, 5 - 35.","Baker, A. N. (1979) Some Ophiuroidea from the Tasman Sea and adjacent waters. New Zealand Journal of Zoology, 6 (1), 21 - 51. https: // doi. org / 10.1080 / 03014223.1979.10428345","Solis-Marin, F. A., Alvarado, J. J., Abreu-Perez, M., Aguilera, O., Ali, J., Bacallado-Aranega, J. J., Barraza, E., Benavides-Serrato, M., Benitez-Villalobos, F., Betancourt-Fernandez, L., Borges, M., Brandt, M., Brogger, M. I., Borrero-Perez, G. H., Buitron- Sanchez, B. E., Campos, L. S., Cantera, J., Clemente, S., Cohen-Renjifo, M., Coppard, S., Costa-Lotufo, L. V., del Valle- Garcia, R., Diaz, Y., Diaz de Vivar, M. E., Diaz-Martinez, J. P., Duran-Gonzales, A., Ephera, L., Escolar, M., Francisco, V., Freire, C. A., Garcia-Arraras, J. E., Gil, D. G., Hadel, V. F., Hearn, A., Hernandez, J. C., Hernandez-Delgado, E. A., Herrera- Moreno, A., Herrero-Perezrul, M. D., Hooker, Y., Honey-Escandon, M. B. I., Lodeiros, C., Luzuriaga, M., Manso, C. L. C., Martin, A., Martinez, M. I., Martinez, S., Moro-Abad, L., Mutschke, E., Navarro, J. C., Neira, R., Noriega, N., Palleiro- Nayar, J. S., Perez, A. F., Perez-Ruzfa, A., Prieto-Rios, E., Reyes, J., Rodriguez, R., Rubilar, T., Sancho-Mejia, T., Sangil, C., Silva, J. R. M. C., Sonnenholzner, J. I., Ventura, C. R., Tablado, A., Tavares, Y., Tiago, C. G., Tuya, F. & Williams, S. M. (2013) Appendix. In: Alvarado-Barrientos, J. J. & Solis-Marin, F. A. (Eds.), Echinoderm research and diversity in Latin America. Springer-Verlag, Berlin, pp. 543 - 658.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","O'Hara, T. D. & Thuy, B. (2022) Biogeography and taxonomy of Ophiuroidea (Echinodermata) from the I ˆ les Saint-Paul and Amsterdam in the southern Indian Ocean. Zootaxa, 5124 (1), 1 - 49. https: // doi. org / 10.11646 / zootaxa. 5124.1.1","Christodoulou, M., O'Hara, T. D., Hugall, A. F. & Martinez-Arbizu, P. (2019) Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology Report, 29, 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Ophiacantha diplasia H.L. Clark, 1911 Fig. 8G‒L Ophiacantha diplasia H.L. Clark, 1911: 209‒211, fig. 97a‒c.— Boolotian & Leighton 1966: 7‒8, fig. 30.— Hendler 1996: 155‒157, fig. 7.16.— Lambert & Austin 2007: 78‒79, fig. 32‒33. Ophiophthalmus diplasia. Kyte 1982: 508. Material examined. 56 individuals at five stations. TALUD X, Sta. 4, 1 ind. (ICML-EMU-11181-A). TALUD XIV, Sta. 1, 1 ind. (ICML-EMU-11180); Sta. 20, 1 ind. (ICML-EMU-11181-B). TALUD XV, Sta. 1, 12 ind. (ICML-EMU-11183) and 4 ind. (ICML-EMU-11949); Sta. 23, 34 ind. (ICML-EMU-11182) and 3 ind. (ICML-EMU-11673). Comparative material. Ophiacantha diplasia H.L. Clark, 1911, holotype, 1 ind.: USNM 24647. Paratypes, 79 ind.: MCZ OPH-3198, MCZ OPH-3199, MCZ OPH-3416, MCZ OPH-3417, MCZ OPH-3418, USNM 25647, USNM 26000, USNM 26247, USNM 26248, USNM 26814, USNM 26927, USNM 26987, USNM 27091, USNM 27215, USNM 27216 (Supplementary file 2). Description (ICML-EMU-11183). DD = 10 mm. Disc circular. Dorsal disc covered by separated granules, those on the margin longer. Primary plates not evident. RS oval, separated (Fig. 8G). Ventral interradii covered by imbricated scales and some granules distally (Fig. 8H). OSh broader than long, diamond-shape with rounded edges. Madreporite with a rounded depression. AdSh longer than broad, slender, meeting in front of OSh. Jaws bearing six papillae at each side; AdShSp elongated, longer than rest; 2AdShSp elongated; LOPa three, similar in shape to 2AdShSp; IPa pointed (Fig. 8I). Arms gradually narrowing distally. First DAP covered by granules; subsequent DAP as long as broad, rhombic, meeting (Fig. 8J). VAP slightly broader than long, pentagonal, slightly separated from each other. LAP with 6‒7 ArSp, large (approximately 2.5 arm segments in length), smooth, dorsalmost the longest. Tentacle pores with two oval TSc, abradial much longer (Fig. 8K). Color pattern in dorsal disc and arms light brown (Fig. 8G, J), beige in ventral view (ethanol preservation) (Fig. 8H). Habitat and distribution. British Columbia, Canada, Oregon and California, USA, and Mexico (H.L. Clark 1911; Lambert & Austin, 2007; Granja-Fernández et al. 2015); 71‒ 1,408 m depth (Maluf 1988; Hendler 1996), sandy and rocky substrates, coral, death coral, and sponges (H.L. Clark 1911). The material examined was collected off western Baja California Sur and in the Gulf of California; 208‒850 m depth. Remarks. Ophiacantha diplasia is highly variable in its external morphology (H.L. Clark 1911; Hendler 1996). The revision of the TALUD specimens and the type material corroborate this. The following morphological plasticity was observed in the examined specimens: 1) variability in oral shields shape, 2) different thickness of adoral shields (slender vs. broad), 3) jaws with up to 7‒8 papillae and presence of 1‒3 IPa, 4) small specimens (DD Ophiacantha diplasia had been transferred to the genus Ophiophthalmus (Kyte 1982) but was subsequently returned to Ophiacantha by Hendler (1996), who suggested that Ophiophthalmus was an invalid homonym (Paterson 1985). However, the homonymy of Ophiophthalmus has been recently disproven by Nethupul et al. (2022), and this genus currently includes five species (O. cataleimmoidus (H.L. Clark, 1911), O. hylacanthus (H.L. Clark, 1911), O. normani, O. relictus (Koehler, 1904), and O. serratus Nethupul, Stöhr & Zhang, 2022) characterized by ovoid and naked RS, 3‒4 spiniform lateral oral papillae, and a short jaw. These characteristics do not coincide with O. diplasia since the latter presents round and short RS, many oral papillae, and an elongated jaw, suggesting that it belongs to the family Ophiotomidae (O’Hara et al. 2018). Previously recorded off western Baja California, in the Gulf of California, and off the Revillagigedo Islands (Granja-Fernández et al. 2015). The material from western Baja California Sur is a new distribution record for this area., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 33-35, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Kyte, M. A. (1982) Ophiacantha abyssa, a new species, and Ophiophthalmus displasia (Clark), a suggested new combination in the ophiuroid family Ophicanthidae (Echinodermata: Ophiuroidea) from off Oregon, U. S. A. Proceedings of the Biological Society of Washington, 95 (3), 505 - 508.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Stohr, S., O'Hara, T. & Thuy, B. (2022) World Ophiuroidea database. Available from: http: // marinespecies. org / aphia. php? p = search (accessed 15 April 2022)","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Nethupul, H., Stohr, S. & Zhang, H. (2022) Review of Ophioplinthaca Verrill, 1899 (Echinodermata, Ophiuroidea, Ophiacanthidae), description of new species in Ophioplinthaca and Ophiophthalmus, and new records from the Northwest Pacific and the South China Sea. ZooKeys, 1099, 155 - 202. https: // doi. org / 10.3897 / zookeys. 1099.76479","Koehler, R. (1904) Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. In: Weber, M., Siboga Expeditie. 45 a. M. E. J. Brill, Leiden, pp. 1 - 176. https: // doi. org / 10.5962 / bhl. title. 11682","O'Hara, T. D., Stohr, S., Hugall, A. F., Thuy, B. & Martynov, A. (2018) Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification. European Journal of Taxonomy, 416, 1 - 35. https: // doi. org / 10.5852 / ejt. 2018.416"]}

Ophiophthalmus normani (Lyman, 1879) Fig. 12A‒F Ophiacantha normani Lyman, 1879: 58‒59, pl. 15, figs. 414‒416.—Lütken & Mortensen 1899: 170‒171, pl. 16, figs. 1‒4.— H.L. Clark 1911: 215‒217.— Boolotian & Leighton 1966: 7‒10, fig. 31.— Lambert & Austin 2007: 80‒81, figs. 34‒35. Ophiophthalmus normani. Koehler 1922: pl. 9, fig. 5‒6.— Kyte 1969a: 1738.— Hendler 2018: 212‒213, fig. 17.— Nethupul et al. 2022: 196. Material examined. 2,254 individuals at 14 stations. TALUD VIII, Sta. 3, 5 ind. (ICML-EMU-11198) and 5 ind. (ICML-EMU-11202-A); Sta. 10, 1 ind. (ICML-EMU-11199-A); Sta. 16, 2 ind. (ICML-EMU-11199-B). TALUD IX, Sta. 21B, 1 ind. (ICML-EMU-11202-B). TALUD X, Sta. 9, 412 ind. (ICML-EMU-11196); Sta. 10, 2 ind. (ICML-EMU-9015), 9 ind. (ICML-EMU-11200), 7 ind. (ICML-EMU-11201), and 941 ind. (ICML-EMU-11219); Sta. 12, 11 ind. (ICML-EMU-11197). TALUD XIII, Sta. B, 1 ind. (ICML-EMU-11203-A); Sta. 34, 3 ind. (ICML-EMU-11203-B); Sta. 37, 1 ind. (ICML-EMU-13000). TALUD XVIB, Sta. 19, 2 ind. (ICML-EMU-11205); Sta. 22, 47 ind. (ICML-EMU-11204); Sta. 23, 22 ind. (ICML-EMU-11206); Sta. 27, 19 ind. (ICML-EMU-11207), 54 ind. (ICML-EMU-11208), 704 ind. (ICML-EMU-11223), and 5 ind. (ICML-EMU-11688). Comparative material. Ophiacantha normani Lyman, 1879, syntypes, 4 ind.: MCZ OPH-1971 (Supplementary file 2). Description (ICML-EMU-11219). DD = 16 mm. Disc circular. Dorsal disc covered by scales and scattered granules. Primary plates not evident. RS oval, separated (Fig. 12A). Ventral interradii covered by scattered granules, longer than dorsal granules. Genital slits with numerous imbricated scales (Fig. 12B). OSh broader than long, slender, diamond-shaped with rounded edges. Madreporite with a rounded depression. AdSh longer than broad, slender, curved, separated from each other. Jaws bearing three papillae at each side; AdShSp elongated, pointed; 2AdShSp similar in shape to AdShSp; IPa similar to AdShSp and 2AdShSp but with widened base. vT pointed, wider than IPa (Fig. 12C). Arms gradually narrowing distally. DAP broader than long, fan-shaped, distal edge with a conspicuous row of pointed granules, meeting on the first segments and separated distally (Fig. 12D). VAP slightly broader than long, pentagonal with a distal notch, separated from each other. LAP with four ArSp, large (approximately three arm segments in length), smooth, dorsalmost the longest. Tentacle pores with one pointed TSc (Fig. 12E). Color pattern brown (ethanol preservation) (Fig. 12A‒F). Habitat and distribution. Japan, the Okhotsk Sea, the Bering Sea, Alaska, USA, Mexico, Costa Rica, and Peru (Lyman 1879; Lambert & Austin 2007; Granja-Fernández et al. 2015; Granja-Fernández & Hooker 2020); 37‒ 3,000 m depth (Lambert & Austin 2007), muddy substrates (Lütken & Mortensen 1899). The material examined was collected off western Baja California and in the Gulf of California; 465‒ 2,195 m depth. Remarks. Ophiophthalmus normani is easily identifiable by its DAP with a conspicuous row of pointed granules on the distal edge, and its disc with scales and granules (except on the radial shields)., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 42-43, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1879) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part II. Bulletin of the Museum of Comparative Zoology at Harvard College, 6 (2), 17 - 83.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Hendler, G. (2018) Armed to the teeth: a new paradigm for the buccal skeleton of brittle stars (Echinodermata: Ophiuroidea). Contribution in Science, 526, 189 - 311. https: // doi. org / 10.5962 / p. 324539","Nethupul, H., Stohr, S. & Zhang, H. (2022) Review of Ophioplinthaca Verrill, 1899 (Echinodermata, Ophiuroidea, Ophiacanthidae), description of new species in Ophioplinthaca and Ophiophthalmus, and new records from the Northwest Pacific and the South China Sea. ZooKeys, 1099, 155 - 202. https: // doi. org / 10.3897 / zookeys. 1099.76479","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Granja-Fernandez, R. & Hooker, Y. (2020). Revisiting the diversity and distribution of the ophiuroids (Echinodermata: Ophiuroidea) from Peru. Zootaxa, 4766 (4), 539 - 556. https: // doi. org / 10.11646 / zootaxa. 4766.4.2"]}

Ophiomitra granifera Lütken & Mortensen, 1899 Fig. 7G‒L Ophiomitra granifera Lütken & Mortensen, 1899: 177‒178, pl. 19, figs. 9‒12. Material examined. 22 individuals at one station. TALUD XII, Sta. 27, 22 ind. (ICML-EMU-12998). Comparative material. Syntypes, 10 ind.: MCZ OPH-2050, MNHN-IE-2013-10260, USNM 19583, USNM 19584 (Supplementary file 2). Description (ICML-EMU-12998). DD = 6.6 mm. Disc rounded, slightly indented interradially. Dorsal disc covered by imbricated scales and scattered thorny granules. Central primary plate evident. RS slightly longer than broad, triangular with rounded edges, separated by a row of scales and granules (Fig. 7G). Ventral interradii short, covered by imbricated scales (Fig. 7H). OSh broader than long, diamond-shape with rounded edges. Madreporite not evident. AdSh longer than broad, semilunar, almost meeting or meeting in front of OSh. Jaws bearing three papillae at each side; AdShSp lanceolate, larger than rest; LOPa and IPa elongated, pointed. vT longer than oral papillae (Fig. 7I). Arms slender, gradually narrowing distally. First two DAP reduced, covered by few granules similar to those on the disc; subsequent DAP longer than broad, triangular with rounded distal edge, slightly separated from each other (Fig. 7J). VAP slightly broader than long, heptagonal, separated from each other. LAP with 5‒6 ArSp, large (approximately 1.5 arm segment in length), serrated; dorsalmost the longest and ventralmost the shortest. One lanceolate TSc (Fig. 7K). Color pattern beige-whitish (ethanol preservation) (Fig. 7G‒L). Habitat and distribution. Only recorded from the Mexican Pacific, off western Baja California, in the Gulf of California, off Nayarit, Colima, and Marias Islands; 267‒ 2,806 m depth, rocky and sandy bottoms (Lütken & Mortensen 1899; Luke 1982; Granja-Fernández et al. 2015, 2021; see Remarks). The material examined was collected off Colima; 1,040 ‒1,095 m depth. Remarks. The collected material presented the following variations: 1) some individuals had radial shields in contact distally or entirely separated, and 2) the central primary plate is present (more common) or not. Ophiomitra granifera easily loses disc granules due to rough handling, which hampers identification since these granules are one of the diagnostic characters of the species; however, each detached granule leaves a fingerprint as a round articular depression in each scale which makes the presence of granules easily identifiable even if they are lost. The record of O. granifera off Colima (18º40′28″N; 104º35′51″W) is an extension of its southernmost distribution limit.

Ophiura flagellata (Lyman, 1878) Fig. 4G‒L Ophioglypha flagellata Lyman, 1878: 69, pl. 2, figs. 49‒51. Gymnophiura coerulescens Lütken & Mortensen, 1899: 114‒116, pl. 7, figs. 4‒6. Ophiura flagellata. H.L. Clark 1911: 61, fig. 15; 1913: 208.— Koehler 1922: 375‒377, pl. 85, figs. 1, 6, 7, pl. 86, figs. 1‒4, 10.— Paterson 1985: 120, fig. 44.— Lambert & Boutillier 2011: 51, fig. 37. Material examined. 57 individuals at eight stations. TALUD VIII, Sta. 3, 3 ind. (ICML-EMU-11143-A), and 1 ind. (ICML-EMU-11716). TALUD IX, Sta. 21B, 1 ind. (ICML-EMU-11143-B). TALUD XII, Sta. 9, 12 ind. (ICML-EMU-11140); Sta. 24, 8 ind. (ICML-EMU-11141); Sta. 27, 4 ind. (ICML-EMU-11142-A); Sta. 29, 5 ind. (ICML-EMU-11142-B). TALUD XV, Sta. 5F, 1 ind. (ICML-EMU-11146); Sta. 9, 18 ind. (ICML-EMU-11145) and 4 ind. (ICML-EMU-11692). Comparative material. Gymnophiura coerulescens Lu ̈tken & Mortensen, 1899, syntypes, 5 ind.: MCZ OPH-786, USNM 19440, USNM 19441 (Supplementary file 2). Description (ICML-EMU-11145). DD = 15 mm. Disc rounded, flat. Dorsal disc covered by minute and imbricated scales. Rays of integument in RS and project from the arms. RS broader than long, circular, separated by numerous scales and the arm width, covering 1/9 of disc radius (Fig. 4G). Ventral interradii covered by irregular imbricated scales, larger than dorsal scales. Genital slits with numerous pointed, small genital papillae; projecting dorsally and forming well-developed arm combs with larger papillae (Fig. 4H). OSh longer than broad, nearly pentagonal. Madreporite not evident. AdSh longer than broad, elongated, slender, meeting in front of OSh. Jaws bearing 4‒5 papillae at each side; BSc, IPa, 2IPa and TPa oval, pointed, all of similar size. vT pointed and larger than oral papillae. Preceding ossicles separated by a diastema: one AdShSp, 4‒5 2AdShSp. Arms gradually narrowing distally (Fig. 4I). DAP broader than long, rectangular, meeting. Longitudinal middle keel along the dorsal arm (Fig. 4J). VAP rhomboidal, meeting, separating and decreasing in size distally. LAP with 3‒4 ArSp, very long (approximately two arm segments in length), pointed, dorsalmost the longest. First tentacle pores with 4‒5 oblong TSc; subsequent tentacle pores with up to six TSc, diminishing in number until reaching one distally (Fig. 4K). Color pattern beige-whitish (Fig. 4G‒L). Radial rays darkening in dorsal disc by a scale-less disc center (ethanol preservation) (Fig. 4G). Habitat and distribution. South Africa, Indonesia, Australia, Japan, Bering Sea, and Alaska. In the eastern tropical Pacific in Mexico and off the Galapagos Islands; 96‒ 2,330 m depth, associated with rocky and muddy bottoms (H.L. Clark 1917; Imaoka et al. 1990; Rowe & Gates 1995; Lambert & Boutillier 2011; Granja-Fernández et al. 2015). The material examined was collected off western Baja California Sur, in the Gulf of California, and off Jalisco, Colima, and Guerrero; 1,035 ‒1,643 m depth. Remarks. It was impossible to examine the type material of Ophiura flagellata. However, O. flagellata features several morphological differences compared to Gymnophiura coerulescens, including the radial shield shape, the arm spines length, the tentacle scales number, and the length of the spines on the arm combs (H.L. Clark 1911; Koehler 1922). The TALUD material examined matches the morphology of G. coerulescens (distributed in the eastern tropical Pacific; Lütken & Mortensen 1899), which probably corresponds to a valid species, but further studies, including material from the valid and synonymous of O. flagellata, are needed to confirm this. Previously known in the Mexican Pacific off western Baja California Sur and in the Gulf of California (Granja-Fernández et al. 2015). Samples of O. flagellata collected off Jalisco, Colima, and Guerrero represent new distribution records for these Mexican Pacific areas., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 22-24, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140.","Wyville-Thomson, C. (1873) The depths of the sea. An account of the general results of the dredging cruises of H. M. S. S. ' Porcupine' and ' Lightning' during the summers of 1868, 1869, and 1870, under the scientific direction of Dr. Carpenter, F. R. S, J. Gwyn Jeffreys, F. R. S., and Dr. Wyville Thomson, F. R. S. Macmillan and Co, London, 527 pp. https: // doi. org / 10.5962 / bhl. title. 19314","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Imaoka, T., Irimura, S., Okutani, T., Oguro, C., Oji, T., Shigei, M. & Horikawa, H. (1990) Echinoderms of the continental shelf and slope around Japan. Vol. 1. Japan Fisheries Resource Conservation Association, Tokyo, 138 pp.","Rowe, F. W. E. & Gates, J. (1995) Echinodermata. CSIRO, Melbourne, 510 pp.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Ophiuroglypha irrorata irrorata (Lyman, 1878) Fig. 6G‒L Ophioglypha irrorata Lyman, 1878: 73‒74, pl. 4, figs. 106‒108. Ophioglypha orbiculata Lyman, 1878: 74‒75, pl. 4, figs. 103‒105. Ophioglypha grandis Verrill, 1894: 293‒295. Ophioglypha tumulosa Lütken & Mortensen, 1899: 120‒122, pl. 1, figs. 9‒13. Ophioglypha involuta Koehler, 1897: 295‒297, pl. 6, figs. 16‒18. Ophioglypha figurata Koehler, 1908: 587‒588, pl. 9, figs. 83‒84. Ophioglypha integra Koehler, 1908: 584‒585, pl. 8, figs. 79‒80. Ophiura irrorata. H.L. Clark 1911: 62‒64; 1913: 209; 1917: 445‒446.— Koehler 1922: 380.— Tommasi 1976: 292, figs. 14‒17, 43‒48.— Martynov & Litvinova 2008: 79‒80, fig. 1c. Ophiura (Ophiuroglypha) irrorata irrorata. Paterson 1985: 123‒124, figs. 46‒47. Ophiuroglypha irrorata. Stöhr & O’Hara 2021: 518‒519, fig. 3c‒d. See Paterson (1985) and Stöhr & O’Hara (2021) for other synonymous records. Material examined. 12 individuals at three stations. TALUD XII, Sta. 8, 1 ind. (ICML-EMU-11144-B); Sta. 15, 1 ind. (ICML-EMU-13001); Sta. 25, 8 ind. (ICML-EMU-11144-A) and 2 ind. (ICML-EMU-11693). Comparative material. Ophioglypha tumulosa Lu ̈tken & Mortensen, 1899, syntypes, 36 ind.: MCZ OPH-613, MCZ OPH-615, MCZ OPH-616, USNM 19451, USNM 19452, USNM 19454, USNM 19455, USNM 19456, USNM 19457, USNM 19458, USNM 19459, USNM 19461 (Supplementary file 2). Description (ICML-EMU-11144-A). DD = 24 mm. Disc rounded. Dorsal disc covered by numerous irregular scales, smallest in the center, largest at disc margin.Central primary plate rounded, separated from the rest of semilunar primary plates. RS slightly broader than long, oval, separated from each other, one oval plate between each pair of RS (Fig. 6G). Ventral interradii covered by imbricated, irregular scales. Genital slits with papilliform genital papillae, projecting dorsally and forming discrete arm combs with oblong short papillae (Fig. 6H). OSh slightly broader than long, pentagonal, rounded distal edge. Madreporite not evident. AdSh longer than broad, elongated, slender, almost meeting or meeting in front of OSh. Jaws bearing 6‒7 papillae at each side; BSc rectangular, elongated; IPa similar in shape but larger than BSc; 2IPa 3‒4 quadrangular, slightly pointed; TPa two pointed, the apicalmost the largest. vT pointed, larger than oral papillae. Preceding ossicles separated by a diastema; one AdShSp, 8‒9 2AdShSp, elongated, rectangular with rounded edges (Fig. 6I). Arms gradually narrowing distally. First 2‒3 DAP broader than long, overlapping; subsequent DAP broader than long, trapezoidal, meeting (Fig. 6J). VAP broader than long, diamond-shaped, separating and decreasing in size distally. LAP with 3‒4 ArSp, minute (approximately 1/4 LAP in length), blunt, one longest and located dorsalmost and 2‒3 separated and located ventralmost. First tentacle pore with 8‒9 elongated, rectangular with rounded edges TSc, distalmost adradial scale enlarged; subsequent tentacle pores with fewer TSc until there is none distally (Fig. 6K). Color pattern beige-whitish (ethanol preservation) (Fig. 6G‒L). Habitat and distribution. Atlantic (including the Caribbean), Pacific, and Indian Oceans; 403‒ 7,340 m depth (Paterson 1985; Martynov & Litvinova 2008). In the eastern tropical Pacific, it is distributed in Mexico, off Coco Island (Costa Rica), Panama, Colombia, Ecuador, the Galapagos Islands, and Peru; muddy and sandy bottoms (Lütken & Mortensen 1899; Solís-Marín et al. 2013). The material examined was collected off Colima and Guerrero; 1,858 ‒2,125 m depth. Remarks. The examination of the type of Ophioglypha tumulosa and the TALUD material of this species indicated that some specimens can have only the central primary plate evident or all the primary plates very conspicuous. Further morphometric analysis is therefore required in order to elucidate if there is any pattern related to the size of individuals. Ophiuroglypa irrorata irrorata is distributed worldwide (Paterson 1985) and is one of the most predominant abyssal species (Martynov & Litvinova 2008). Moreover, it belongs to the group “ Ophiura irrorata ” proposed by Paterson (1985), which includes species and subspecies sharing the character of an enlarged distal tentacle scale on the proximal tentacle pores. Ophiura irrorata constitute a species complex with unclear morphological differences, which have been interpreted as intraspecific variability; according to recent studies, Indo-Pacific and Pacific oceans specimens concur with O. irrorata irrorata (Christodoulou et al. 2019; Stöhr & O’Hara 2021). Further morphometric and molecular analyses are needed to corroborate if the subspecies from the eastern Pacific are similar to the material from the rest of the world or not. Records off Colima and Guerrero are new for these areas and fill the distribution gap of this species in the Mexican Pacific., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 28-30, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Verrill, A. E. (1894) Descriptions of new species of starfishes and ophiurans, with a revision of certain species formerly described; mostly from the collections made by the United States Commission of Fish and Fisheries. Proceedings of the United States National Museum, 17 (1000), 245 - 297. https: // doi. org / 10.5479 / si. 00963801.1000.245","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Koehler, R. (1897) Echinodermes recueillis par \" l'Investigator \" dans l'Ocean Indien. I. Les Ophiures de mer profonde. Annales des Sciences Naturelles Zoologie, series 8, 4, 277 - 372.","Koehler, R. (1908) Asteries, Ophiures et Echinides de l'Expedition Antarctique Nationale Ecossaise. Transactions of the Royal Society of Edinburgh, 46 (22), 529 - 649. https: // doi. org / 10.1017 / S 008045680000380 X","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Tommasi, L. R. (1976) Ophiuroidea collected in the Peru-Chile trench by the USNS \" Eltanin \" during Cruise III. Papeis Avulsos de Zoologia, 29 (8), 281 - 318.","Martynov, A. V. & Litvinova, N. M. (2008) Deep-water Ophiuroidea of the northern Atlantic with descriptions of three new species and taxonomic remarks on certain genera and species. Marine Biology Research, 4 (1 - 2), 76 - 111. https: // doi. org / 10.1080 / 17451000701840066","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Stohr, S. & O'Hara, T. D. (2021) Deep-sea Ophiuroidea (Echinodermata) from the Danish Galathea II Expedition, 1950 - 52, with taxonomic revisions. Zootaxa, 4963 (3), 505 - 529. https: // doi. org / 10.11646 / zootaxa. 4963.3.6","Solis-Marin, F. A., Alvarado, J. J., Abreu-Perez, M., Aguilera, O., Ali, J., Bacallado-Aranega, J. J., Barraza, E., Benavides-Serrato, M., Benitez-Villalobos, F., Betancourt-Fernandez, L., Borges, M., Brandt, M., Brogger, M. I., Borrero-Perez, G. H., Buitron- Sanchez, B. E., Campos, L. S., Cantera, J., Clemente, S., Cohen-Renjifo, M., Coppard, S., Costa-Lotufo, L. V., del Valle- Garcia, R., Diaz, Y., Diaz de Vivar, M. E., Diaz-Martinez, J. P., Duran-Gonzales, A., Ephera, L., Escolar, M., Francisco, V., Freire, C. A., Garcia-Arraras, J. E., Gil, D. G., Hadel, V. F., Hearn, A., Hernandez, J. C., Hernandez-Delgado, E. A., Herrera- Moreno, A., Herrero-Perezrul, M. D., Hooker, Y., Honey-Escandon, M. B. I., Lodeiros, C., Luzuriaga, M., Manso, C. L. C., Martin, A., Martinez, M. I., Martinez, S., Moro-Abad, L., Mutschke, E., Navarro, J. C., Neira, R., Noriega, N., Palleiro- Nayar, J. S., Perez, A. F., Perez-Ruzfa, A., Prieto-Rios, E., Reyes, J., Rodriguez, R., Rubilar, T., Sancho-Mejia, T., Sangil, C., Silva, J. R. M. C., Sonnenholzner, J. I., Ventura, C. R., Tablado, A., Tavares, Y., Tiago, C. G., Tuya, F. & Williams, S. M. (2013) Appendix. In: Alvarado-Barrientos, J. J. & Solis-Marin, F. A. (Eds.), Echinoderm research and diversity in Latin America. Springer-Verlag, Berlin, pp. 543 - 658.","Christodoulou, M., O'Hara, T. D., Hugall, A. F. & Martinez-Arbizu, P. (2019) Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology Report, 29, 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012"]}

Ophiopsila californica A.H. Clark, 1921 Fig. 13G‒L Ophiopsila californica A.H. Clark, 1921: 109‒110.— Boolotian & Leighton 1966: 6‒10, fig. 24. Material examined. One individual at one station. TALUD XIV, Sta. 7, 1 ind. (ICML-EMU-11689). Comparative material. Holotype: USNM 38662 (Supplementary file 2). Description (ICML-EMU-11689). DD = 12 mm. Disc rounded. Dorsal disc covered by very fine and imbricated scales, no granules or spines. Primary plates not evident. RS elongated, slender, conspicuous distally, separated by numerous scales proximally (Fig. 13G). Ventral interradii covering similar to dorsal disc (Fig. 13H). OSh broader than long, triangular with rounded edges, and with a distal protuberance. Madreporite larger than OSh. AdSh slender, not conspicuous, separated. Jaws bearing 2‒3 oval AdShSp and 2AdShSp; BSc elongated; IPa elongated, pointed; TPa numerous, elongated, strong, various sizes. vT rectangular (Fig. 13I). Arms slender and elongated. DAP broader than long, rectangular with rounded edges, meeting (Fig. 13J). VAP longer than broad, pentagonal, meeting. LAP with five ArSp, small (approximately 1.5 arm segment in length), flat tip, ventralmost the longest. Tentacle pores with two TSc, adradial lanceolate and extremely elongated crossing the opposite adradial TSc, abradial TSc pointed and small (approximately ¼ VAP in length) (Fig. 13K). Color pattern on dorsal and ventral disc beige with brown spots (Fig. 13G, H), dorsal arms with transverse brown and beige bands, and some white stains (ethanol preservation) (Fig. 13J, L). Habitat and distribution. California, EUA, and northern Mexican Pacific; 33‒ 204 m depth, rocky and sandy substrates (A.H. Clark 1921; Maluf 1988; Granja-Fernández et al. 2015; see Remarks). The material examined was collected in the northern Gulf of California; 204 m depth. Remarks. Previously known as deep as 201 m (Maluf 1988) but recorded herein at 204 m depth. The original description of Ophiopsila californica is based on a small specimen (DD = 4.5 mm; A.H. Clark 1921). The unique specimen examined herein allows for the first description and the first photographic record of a large specimen., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 47, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, A. H. (1921) A new ophiuran of the genus Ophiopsila from Southern California. Proceedings of the Biological Society of Washington, 34, 109 - 110.","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Asteronyx longifissus Döderlein, 1927 Fig. 1A‒F Asteronyx longifissus Döderlein, 1927: 65‒68, pl. 7, figs. 1‒3.— A.M. Clark 1965: 68.— Hendler 1996: 123‒125, fig 7.2; 2018: 194‒198, fig. 1. Material examined. 164 individuals at five stations. TALUD VIII, Sta. 11, 2 ind. (ICML-EMU-11108); Sta. 20, 1 ind. (ICML-EMU-11095). TALUD XV, Sta. 20, 159 ind. (ICML-EMU-11098); Sta. 23, 1 ind. (ICML-EMU-11109); Sta. 24, 1 ind. (ICML-EMU-11699). Comparative material. Syntypes, 324 ind.: USNM E4061, USNM E4067, USNM E4069, USNM E4076, USNM E4081, USNM E4096, USNM E4109, USNM E4112, USNM E4117, USNM E4118, USNM E4120, USNM E4121, USNM E4242, USNM E4246 (Supplementary file 2). Description (ICML-EMU-11699). DD = 16 mm. Disc pentagonal, flat, indented interradially. Dorsal disc with thickened skin, lacking scales. RS multilayered, very prominent distally, almost reaching the center of the disc (Fig. 1A). Ventral interradii entirely covered by integument with some granule-shaped epidermal ossicles proximally. Genital slits oval, restricted to middle-distal part, elongate, covering approximately 3/4 of the interradius (Fig. 1B). OSh broader than long, rounded triangular. Madreporite not evident. AdSh broader than long, rectangular with rounded edges, separated by integument. Jaws bearing 8‒9 papillae at each side; OPa 4‒5, spiniform, elongated, separated; TPa four at jaw tips, spiniform, larger than OPa, separated. Teeth several, similar to TPa (Fig. 1C). Arms entirely covered by integument, coiled, gradually narrowing distally (Fig. 1D). LAP located on the ventral lateral side of vertebrae, short and rounded, prominent (Fig. 1E). First and second tentacle pores outside the mouth lacking ArSp; third to eight pores with one ArSp with serrated tip; subsequent pores with 2‒3 ArSp, hook-shaped, serrated, gradually reaching up to six in the middle of the arm; distal tentacle pores with four ArSp, ventralmost ArSp elongated. TSc lacking (Fig. 1E). Color pattern yellowish-brown (ethanol preservation) (Fig. 1A‒F). Habitat and distribution. From Oregon, USA, to Northern Mexico; 265‒ 1,800 m depth (Döderlein 1927; Maluf 1988; see Remarks). Associated with sea pens (Duffy et al. 2014). The material examined was collected off western Baja California Sur and in the southern Gulf of California; 530‒ 1,150 m depth. Remarks. Examination of the TALUD specimens and the type material of this species demonstrated that the oral shields can be partially or completely concealed or can be completely visible. Moreover, some specimens can have radial shields almost reaching the center of the disc or cover 3/4 of the diameter of the disc; this could be an artifact caused by preservation because of potential contraction of the soft disc, thus modifying the appearance of the radial shield coverage (pers. comm. Sabine Stöhr, 2022). Asteronyx longifissus has been previously recorded in Mexico only for western Baja California Sur and Guerrero (Honey-Escandón et al. 2008). Material from Guerrero is deposited at ICML-UNAM (ICML-UNAM 3.140.2, Isla de Ixtapa) and was examined. Morphological differences such as radial shields not multilayered, minute spines in the dorsal disc, and OPa not granule-like were observed. We conclude that the material from Guerrero does not correspond to A. longifissus but probably to a species new to science, and this record should be considered invalid. The discovery of A. longifissus during the Gulf of California cruises is a first for this area. This species is now known to range as far north as 25º56′N. Due to its northern affinity and the invalidation of the record in Guerrero, we suggest that A. longifissus distribution is probably limited to temperate waters in the northern American Pacific., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 13, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Doderlein, L. (1927) Indopacifische Euryalae. Abhandlungen der Mathematisch-Physikalischen Klasse der Koniglich Bayer Akademie der Wissenschaften, 31 (6), 1 - 105. https: // doi. org / 10.1515 / 9783486755459","Clark A. M. (1965). Japanese and other ophiuroids from the collections of the Mu ¨ nich Museum. Bulletin of the British Museum (Natural History) Zoology, 13, 37 - 71. https: // doi. org / 10.5962 / p. 271717","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Duffy, G. A., Lundsten, L., Kuhnz, L. A & Paull, C. K. (2014) A comparison of megafaunal communities in five submarine canyons off Southern California, USA. Deep-Sea Research II, 104 (2014), 259 - 266. https: // doi. org / 10.1016 / j. dsr 2.2013.06.002","Stohr, S., O'Hara, T. & Thuy, B. (2022) World Ophiuroidea database. Available from: http: // marinespecies. org / aphia. php? p = search (accessed 15 April 2022)","Honey-Escandon, M., Solis-Marin, F. A. & Laguarda-Figueras, A. (2008) Equinodermos (Echinodermata) del Pacifico Mexicano. Revista de Biologia Tropical, 56 (3), 57 - 73."]}

Astrodia excavata (Lütken & Mortensen, 1899) Fig. 2A‒G Asteronyx excavata Lütken & Mortensen, 1899: 185‒186, pl. 22, figs. 2‒6.—H.L. Clark 1913: 219; 1923: 157.— Döderlein 1927: 59, 98. Astrodia excavata. Okanishi & Fujita 2014: 192‒195, figs. 5‒7. Material examined. 58 individuals at eight stations. TALUD IV, Sta. 19, 1 ind. (ICML-EMU-11094). TALUD VIII, Sta. 11, 1 ind. (ICML-EMU-11096). TALUD XII, Sta. 23, 1 ind. (ICML-EMU-11093); Sta. 27, 17 ind. (ICML-EMU-11114); Sta. 28, 1 ind. (ICML-EMU-11097). TALUD XV, Sta. 23, 6 ind. (ICML-EMU-11100); Sta. 24, 26 ind. (ICML-EMU-11099), 1 ind. (ICML-EMU-11101), and 3 ind. (ICML-EMU-11697). TALUD XVIB, Sta. 17, 1 ind. (ICML-EMU-11102). Comparative material. Asteronyx excavata Lütken & Mortensen, 1899, lectotype, 1 ind.: MCZ OPH-2817. Paralectotype, 1 ind.: USNM 19598. Syntype, 1 ind.: USNM 19599 (Supplementary file 2). Description (ICML-EMU-11099). DD = 24.7 mm. Disc five-lobed, indented interradially. Dorsal disc covered with thickened skin, lacking scales. RS coarse, surrounded by epidermal ossicles, very prominent, almost reaching the center of the disc (Fig. 2A). Ventral interradii covered by integument and external ossicles. Genital slits oval, restricted to proximal-middle part, elongated, covering approximately 3/4 of the interradius (Fig. 2B). OSh broader than long, triangular. One madreporite, larger than OSh. AdSh broader than long, with rounded edges, meeting or almost meeting proximally. Jaws bearing six papillae at each side; OPa four, granule-like, distalmost papilla larger, rectangular-shaped; TPa two at jaw tips, spiniform, larger than OPa. Teeth several, similar to TPa (Fig. 2C). Arms entirely covered by integument, coiled, thick, gradually narrowing distally. LAP located on the ventral lateral side of vertebrae, bar-like, prominent (Fig. 2D). First to fourth tentacle pores lacking ArSp; fifth to ninth with one ArSp (Fig. 2E); subsequent pores with 3‒4 ArSp, 2‒3 serrated, one ventralmost elongated (approximately 1.5 VAP in length), bulbous, serrated at the tip, not hooked (Fig. 2F). TSc lacking. Color pattern brownish-beige (ethanol preservation) (Fig. 2A‒G). Habitat and distribution. California, USA to Mexico (Luke 1982; Granja-Fernández et al. 2015); doubtful record in Peru (Granja-Fernández & Hooker 2020); 267‒ 1,273 m depth (Okanishi & Fujita 2014), associated with rocks and gorgonians (Lütken & Mortensen 1899; H.L. Clark 1923). The material examined is from off western Baja California and Baja California Sur, the southern Gulf of California, and off Colima; 530‒ 1,245 m depth, associated with unidentified gorgonians. Remarks. In Mexico, Astrodia excavata has been recorded in western Baja California and Baja California Sur, the Gulf of California, and Marias Islands (Granja-Fernández et al. 2015). Present records in Colima represent a significant extension of its distribution to the south (to 18º33′43″N; 103º57′45″W) in western Mexico. GranjaFernández & Hooker (2020) suggested that the Peruvian record of A. excavata is doubtful and needs taxonomical confirmation. If further revision of the material from Peru indicates that this record is incorrect, then Colima (TALUD XII, Sta. 23) will be the southernmost distribution limit for this species., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 16, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Clark, H. L. (1923) Echinoderms from Lower California with descriptions of new species: supplementary report. Bulletin of the American Museum of Natural History, 48 (6), 147 - 163.","Doderlein, L. (1927) Indopacifische Euryalae. Abhandlungen der Mathematisch-Physikalischen Klasse der Koniglich Bayer Akademie der Wissenschaften, 31 (6), 1 - 105. https: // doi. org / 10.1515 / 9783486755459","Okanishi, M. & Fujita, T. (2014) A taxonomic review of the genus Astrodia (Echinodermata: Ophiuroidea: Asteronychidae). Journal of the Marine Biological Association of the United Kingdom, 94 (1), 187 - 201. https: // doi. org / 10.1017 / S 0025315413001331","Luke, S. R. (1982) Catalog of benthic invertebrate collections, Echinodermata. Scripps Institution of Oceanography series, no. 82 - 5, University of California, 66 pp.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Granja-Fernandez, R. & Hooker, Y. (2020). Revisiting the diversity and distribution of the ophiuroids (Echinodermata: Ophiuroidea) from Peru. Zootaxa, 4766 (4), 539 - 556. https: // doi. org / 10.11646 / zootaxa. 4766.4.2"]}

Amphiura carchara H.L. Clark, 1911 Fig. 14G‒L Amphiura carchara H.L. Clark, 1911: 142‒143, fig. 55.— Martynov 2010: figs. 15m, 31f. Pandelia carchara. Fell 1962: 10.— Kyte 1969a: 1737. Material examined. 31 individuals at three stations. TALUD XVIB, Sta. 22, 1 ind. (ICML-EMU-11149-A) and 4 ind. (ICML-EMU-11149-B); Sta. 26, 1 ind. (ICML-EMU-11149-C); Sta. 27, 10 ind. (ICML-EMU-11150) and 15 ind. (ICML-EMU-11667). Comparative material. Holotype: USNM 25594. Paratypes, 158 ind.: MCZ OPH-3140, MCZ OPH-3141, MCZ OPH-3370, USNM 25993, USNM 26053, USNM 26114, USNM 26115, USNM 26213, USNM 26615, USNM 27017, USNM 27018, USNM 27054, USNM 32377, USNM 33639 (Supplementary file 2). Description (ICML-EMU-11667). DD = 7 mm. Disc rounded. Dorsal disc covered by imbricated scales. Primary plates oval, separated from each other by scales. RS triangular with rounded edges, in contact only distally, the rest separated by scales (Fig. 14G). Ventral interradii covered by integument, distally with a fold of scales (Fig. 14H). OSh broader than long, bell-shaped with rounded edges, a distal lobe. Madreporite not evident. AdSh triangular, wider distally, meeting in front of OSh or separated. Jaws bearing three oral papillae at each side; AdShSp elongated, pointed; BSc elongated, pointed; IPa quadrangular with rounded edges, strong. vT elongated with straight edge (Fig. 14I). Arms slender. DAP broader than long, fan-shaped with rounded edges, contiguous (Fig. 14J). VAP longer than broad, pentagonal, slightly separated from each other. LAP with three ArSp, small (approximately 1.5 arm segment in length), pointed, middle ArSp stronger than rest. Tentacle pores with one oval TSc (Fig. 14K). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 14G‒L). Habitat and distribution. Bering Sea, Gulf of Alaska, Washington, USA, and northwestern Mexico (H.L. Clark 1911; Granja-Fernández et al. 2015); 568‒ 3,611 m depth, sandy and muddy substrates (H.L. Clark 1911; Maluf 1988). The material examined was collected in northwestern Baja California; 982‒ 1,560 m depth. Remarks. Examination of the types and the material available herein showed that the morphology in Amphiura carchara is very constant. The only variation observed during this study was the presence of round and separated primary plates in specimens with a DD 6 mm., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 48-50, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Martynov, A. (2010) Reassessment of the classification of the Ophiuroidea (Echinodermata), based on morphological characters. I. General character evaluation and delineation of the families Ophiomyxidae and Ophiacanthidae. Zootaxa, 2697 (1), 1 - 154. https: // doi. org / 10.11646 / zootaxa. 2697.1.1","Fell, B. H. (1962) A revision of the major genera of Amphiuroid Ophiuroidea. Transactions of the Royal Society of New Zealand, Zoology, 2 (2), 1 - 26.","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306."]}

Ophiocnida californica Ziesenhenne, 1940 Fig. 17G‒L Ophiocnida californica Ziesenhenne, 1940: 25‒27, pl. 5, figs. 4‒6.— Granja-Fernández et al. 2014: 109. Material examined. Seven individuals at one station. TALUD XIV, Sta. 32, 3 ind. (ICML-EMU-11174), 3 ind. (ICML-EMU-11175), and 1 ind. (ICML-EMU-11678). Comparative material. Holotype: LACM 615.1. Paratypes, 32 ind.: ICML-UNAM 3.76.0, LACM 615.2, LACM 615.3, LACM 615.4, LACM 615.5, MCZ OPH-7032, USNM E8007 (Supplementary file 2). Description (ICML-EMU-11175). DD = 6 mm. Disc circular. Dorsal disc covered by imbricated scales and scattered small spines mostly around the margin of the disc. Primary plates rounded, widely separated from each other. RS almost bar-like, separated by elongated scales for half their length (Fig. 17G). Ventral interradii covered by imbricated scales smaller than dorsal disc (Fig. 17H). OSh broader than long, spearhead-shaped. Madreporite slightly larger than OSh. AdSh trapezoidal, meeting in front of OSh. Jaws bearing three oral papillae at each side; AdShSp slightly serrated, rectangular, the largest; 2AdShSp pointed; IPa quadrangular-rounded. vT quadrangular (Fig. 17I). Arms slender. DAP twice as wide as long, triangular, some fragmented in 2‒3 pieces, contiguous (Fig. 17J). VAP slightly broader than long, pentagonal, contiguous. LAP with up to three arm spines, small (approximately one arm segment in length), blunt-tip, middle the longest, dorsalmost the shortest. Tentacle pores with two oval TSc (Fig. 17K). Color pattern dorsally and ventrally light brown (ethanol preservation) (Fig. 17G‒L). Habitat and distribution. Gulf of California, Mexico; 5‒302 m depth, coral, algae, sandy, muddy, and rocky substrates (Ziesenhenne 1940; pers. obs.). The material examined was collected only in one locality in the Gulf of California; 123 m depth. Remarks. In some specimens of O. californica collected during this survey, the central primary plate is always evident, contrary to the radial primary plates, which are not always conspicuous. In addition, the fragmentation of the dorsal arm plates is not always very evident, the serration of the AdShSp is sometimes conspicuous and sometimes not. Finally, the ventral arm plates are usually triangular. Other Ophiocnida species have scattered spines on the dorsal disc as in O. californica; however, they differ in having all oral papillae rounded and small (vs. AdShSp slightly serrated and rectangular in O. californica), non-fragmented dorsal arm plates (vs. fragmented), and tentacle scales arranged perpendicularly (vs. arranged in parallel) (e.g., Gondim et al. 2013; Granja-Fernández et al. 2014). Due to these differences, a revision of the generic placement of O. californica is needed., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 57, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Ziesenhenne, F. C. (1940) New Ophiurans of the Allan Hancock Pacific Expeditions. Allan Hancock Pacific Expeditions, 8 (2), 9 - 52.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez, L., Rodriguez-Zaragoza, F. A., Jones, R. W. & Pineda-Lopez, R. (2014) Ophiuroidea (Echinodermata) from coral reefs in the Mexican Pacific. ZooKeys, 406, 101 - 145. https: // doi. org / 10.3897 / zookeys. 406.6306","Gondim, A. I., Alonso, C., Dias, T. L. P., Manso, C. L. C. & Christoffersen, M. L. (2013) A taxonomic guide to the brittle-stars (Echinodermata, Ophiuroidea) from the State of Paraiba continental shelf, Northeastern Brazil. ZooKeys, 307, 45 - 96. https: // doi. org / 10.3897 / zookeys. 307.4673"]}

Ophiosphalma glabrum (Lütken & Mortensen, 1899) Fig. 2H‒M Ophiomusium glabrum Lütken & Mortensen, 1899: 132‒123, pl. 4, figs. 7‒9.—H.L. Clark 1913: 213; 1917: 449‒450.— Koehler 1922: 405. Ophiomusium multispinum H.L. Clark, 1911: 113‒114, fig. 42.— Baker 2016: 31. Ophiomusium fimbriatum Koehler, 1922: 403‒405, pl. 90, figs. 6‒8.— Baker 2016: 31. Ophiosphalma glabrum. Baker 2016: 31, figs. 51a‒d. Material examined. 367 individuals at six stations. TALUD XII, Sta. 8, 20 ind. (ICML-EMU-11060); Sta. 15, 3 ind. (ICML-EMU-11072); Sta. 25, 288 ind. (ICML-EMU-11061), 14 ind. (ICML-EMU-11062), 7 ind. (ICML-EMU-11066), and 3 ind. (ICML-EMU-11683). TALUD XVIB, Sta. 1, 1 ind. (ICML-EMU-11092); Sta. 9, 1 ind. (ICML-EMU-11064-A), 14 ind. (ICML-EMU-11064-B), and 2 ind. (ICML-EMU-11065); Sta. 15, 14 ind. (ICML-EMU-11063). Comparative material. Ophiomusium glabrum Lütken & Mortensen, 1899, syntypes, 86 ind.: MCZ OPH-452, MCZ OPH-453, MCZ OPH-454, MCZ OPH-455, MCZ OPH-780, MCZ OPH-880, MCZ OPH-1021, MNHN-IE-2013-10254, USNM 19494, USNM 19496, USNM 19498, USNM 19499, USNM 19500 (Supplementary file 2). Description (ICML-EMU-11061). DD = 31 mm. Disc pentagonal, flat. Dorsal disc covered with imbricated, irregular scales. RS longer than broad, prominent, separated by numerous elongated scales of different sizes; one triangular plate with rounded edges between each pair of RS (Fig. 2H). Ventral interradii covered by oval imbricated scales, larger than dorsal scales. Genital slits with numerous quadrangular papillae (Fig. 2I). OSh almost as broad as long, triangular. One irregular madreporite, slightly larger than OSh. AdSh longer than broad, elongated, broader distally, meeting in front of OSh. Jaws bearing 6‒7 papillae at each side, quadrangular, merging, two distalmost the largest; one pointed papilla at jaw tips. Teeth four, similar to papilla at jaw tips (Fig. 2J). Arms gradually narrowing distally. Dorsal arm base with 3‒4 imbricated DAP, with a granular appearance, projecting laterally. DAP as long as broad, rhombic, proximally meeting and gradually separating and decreasing in size distally (Fig. 2K). First VAP smaller than rest; subsequent three VAP the largest (almost covering all arm segment length), almost meeting, the only ones with tentacle pores; posterior VAP triangular, reduced in size (1/3 arm segment in length), separated from each other. LAP with 6‒9 ArSp, short (approximately 1/5 LAP in length), pointed, separated; ventralmost ArSp slightly longest than rest. Three tentacle pores with one abradial pointed TSc (approximately 3.5 arm segments in length) and 1‒2 smaller adradial TSc (Fig. 2L). Color pattern beige (Fig. 2H‒M), center of dorsal disc light brown (ethanol preservation) (Fig. 2H). Habitat and distribution. Widely distributed in the eastern Pacific: British Columbia, Canada, Washington, USA, Mexico, Costa Rica, Panama, Colombia, Ecuador, and Peru; 878‒ 5,203 m depth, muddy substrates (Lütken & Mortensen 1899; Luke 1982; Maluf 1988; Lambert & Boutillier 2011). The material examined was collected off western Baja California, Colima, and Guerrero; 1,858 ‒2,125 m depth. Remarks. The specimens of the ICML-EMU-11061 lot presented some morphological differences compared to specimens of the type series, including: 1) three and rarely five tentacle pores, 2) the largest specimens can have up to 12 arm spines, and 3) some specimens have conspicuous primary plates. In Mexico, O. glabrum has been documented in western Baja California and Baja California Sur, the Gulf of California, and Oaxaca (GranjaFernández et al. 2015). The material examined herein was collected off Colima and Guerrero, representing new records for these areas, thus filling the previously known distribution gap in western Mexico., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 16-17, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Baker, A. N. (2016) An illustrated catalogue of type specimens of the bathyal brittlestar genera Ophiomusium Lyman and Ophiosphalma H. L. Clark (Echinodermata: Ophiuroidea). Zootaxa, 4097 (1), 1 - 40. https: // doi. org / 10.11646 / zootaxa. 4097.1.1","Luke, S. R. (1982) Catalog of benthic invertebrate collections, Echinodermata. Scripps Institution of Oceanography series, no. 82 - 5, University of California, 66 pp.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140."]}

Ophiacantha pacifica Lütken & Mortensen, 1899 Fig. 10A‒F Ophiacantha pacifica Lütken & Mortensen, 1899: 166‒167, pl. 15, figs. 4‒6, pl. 16, fig. 11.— Stöhr & O’Hara 2021: 520‒523, fig. 4a‒d. Material examined. 622 individuals at seven stations. TALUD VIII, Sta. 11, 9 ind. (ICML-EMU-11193-A); Sta. 22, 28 ind. (ICML-EMU-11193-B). TALUD IX, Sta. 14, 3 ind. (ICML-EMU-11192-A); Sta. 15, 1 ind. (ICML-EMU-11192-B); Sta. 22, 8 ind. (ICML-EMU-9013-A) and 1 ind. (ICML-EMU-9013-B). TALUD XII, Sta. 27, 6 ind. (ICML-EMU-11194). TALUD XIII, Sta. 37, 561 ind. (ICML-EMU-11195) and 5 ind. (ICML-EMU-11675). Comparative material. Syntypes, 28 ind.: MCZ OPH-1972, MCZ OPH-2199, USNM 19559 (Supplementary file 2). Description (ICML-EMU-11195). DD = 7 mm. Disc pentagonal, flat. Dorsal disc densely covered by slender multifid spines. Primary plates not evident. RS longer than broad, slender, covered by scales and multifid spines, very conspicuous distally (Fig. 10A). Ventral interradii covered by scales and spines similar to those on the dorsal side (Fig. 10B). OSh broader than long, diamond-shape. Madreporite larger than OSh. AdSh longer than broad, larger than oral OSh, almost meeting or meeting in front of OSh. Jaws bearing 3‒4 erected, lanceolate papillae at each side; AdShSp pointed; LOPa 1‒2 similar in shape to AdShSp; IPa lanceolate, pointed. vT shortest than oral papillae (Fig. 10C). Arms slender. DAP almost as long as broad, triangular with rounded edges, separated from each other (Fig. 10D). VAP broader than long, pentagonal with rounded edges, separated from each other. LAP with five ArSp, large (almost one arm segment in length), slender, smooth, blunt, dorsalmost much largest. One pointed TSc, shorter than VAP, size diminishes distally (Fig. 10E). Color pattern brown dorsally and beige ventrally (ethanol preservation) (Fig. 10A‒F). Habitat and distribution. Southern California, USA, Mexico, and Ecuador; 362‒ 2,877 m depth, muddy and sandy substrates (Maluf 1988; Hendrickx 2012a; See Remarks).The material examined was collected in the southern Gulf of California; 920‒ 2,309 m depth. Remarks. According to the examination of the type material and the TALUD samples, specimens of Ophiacantha pacifica present: 1) pentagonal or rounded disc, 2) radial shields partially covered by multifid spines or naked, and 3) larger individuals (DD> 10 mm) with four oral papillae at each side of a jaw as well as up to six arm spines. Additional variations were observed by Stöhr & O’Hara (2021), who suggested that O. pacifica belongs to a species complex conformed by Ophiacantha bathybia H.L. Clark, 1911, Ophiacantha cosmica Lyman, 1878, and Ophiacantha sociabilis Koehler, 1897. Ophiacantha pacifica was tentatively recorded in Mexico by Hendrickx (2012a) and Granja-Fernández et al. (2015); its presence in Mexican waters is hereby confirmed (Gulf of California)., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 37-39, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Stohr, S. & O'Hara, T. D. (2021) Deep-sea Ophiuroidea (Echinodermata) from the Danish Galathea II Expedition, 1950 - 52, with taxonomic revisions. Zootaxa, 4963 (3), 505 - 529. https: // doi. org / 10.11646 / zootaxa. 4963.3.6","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Hendrickx, M. E. (2012 a) Listado sistematico de los equinodermos de aguas profundas del Pacifico mexicano. In: Zamorano, P., Hendrickx, M. E. & Caso, M. (Eds.), Biodiversidad y comunidades del talud continental del Pacifico mexicano. Secretaria del Medio Ambiente y Recursos Naturales (SEMARNAT), Instituto Nacional de Ecologia (INE), Mexico, D. F., pp. 373 - 395.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Koehler, R. (1897) Echinodermes recueillis par \" l'Investigator \" dans l'Ocean Indien. I. Les Ophiures de mer profonde. Annales des Sciences Naturelles Zoologie, series 8, 4, 277 - 372.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Amphipholis pugetana (Lyman, 1860) Fig. 16G‒L Amphiura pugetana Lyman, 1860: 193‒194. Amphipholis pugetana. H.L. Clark 1911: 166‒167.— Nielsen 1932: 281, 288‒290.— Fell 1962: 13, 24.— Lambert & Austin 2007: 102‒104, figs. 55‒56.— Boolotian & Leighton 1966: 5, 9, fig. 9.— Hendler 1996: 140‒142, fig. 7.9. Axiognatus pugetana. Kyte 1969a: 1728, 1735, 1737. See Hendler (1996) for other synonymous records. Material examined. 132 individuals at five stations. TALUD X, Sta. 4, 1 ind. (ICML-EMU-11162-A) and 16 ind. (ICML-EMU-11162-B). TALUD XIV, Sta. 15, 57 ind. (ICML-EMU-11163), 5 ind. (ICML-EMU-11164), and 28 ind. (ICML-EMU-11164-A); Sta. 20, 5 ind. (ICML-EMU-11164-B). TALUD XV, Sta. 20, 1 ind. (ICML-EMU-11165) and 2 ind. (ICML-EMU-12994); Sta. 23, 17 ind. (ICML-EMU-11166). Comparative material. None available. According to Lyman (1860), the type series of A. pugetana was deposited at the USNM, but this material has not been located in this collection or in any other collection (i.e., LACM, MCZ, NHMD; pers. comm. Tom Schiøtte & Penny Benson, 2016) and is probably lost. Description (ICML-EMU-11163). DD = 4 mm. Disc pentagonal. Dorsal disc covered by imbricated scales. Primary plates not evident. RS elongated half-circular, contiguous but with 1‒2 scales inserted proximally (Fig. 16G). Ventral interradii covered by scales smaller than dorsal disc (Fig. 16H). OSh as broad as long, spearhead-shaped. Madreporite slightly larger than OSh. AdSh triangular, meeting in front of OSh. Jaws bearing three oral papillae at each side; AdShSp twice as wide as high, rounded rectangular, the largest; 2AdShSp rounded; IPa quadrangular. vT quadrangular (Fig. 16I). Arms slender. DAP fan-shaped, as long as wide, separated (Fig. 16J). VAP longer than broad, pentagonal, slightly separated from each other. LAP with up to three ArSp, elongated (approximately two arm segments in length), pointed, middle one often much longer and swollen at the tip. Tentacle pores with two TSc, abradial larger (Fig. 16K). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 16G‒L). Habitat and distribution. Alaska, British Columbia, Canada, Washington, and California, USA, and Mexico; 15‒ 871 m depth, possibly to 1,620 m (H.L. Clark 1911; Hendler 1996; Lambert & Austin 2007; Granja-Fernández et al. 2015, 2021; See Remarks), buried in sand and mud (Maluf 1988). The material examined was collected off western Baja California Sur and in the northern Gulf of California; 410‒871 m depth. Some specimens were attached to a log. Remarks. We could not compare our material with the type material (presumably lost), but its morphology is consistent with previous species descriptions (e.g., Lyman 1860; Hendler 1996). Previously recorded from shallow water and as deep as 604 m, and possibly to 1,620 m (Hendler 1996). Our finding of the species at 871 m depth corresponds to the deepest confirmed record to date., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 52, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1860) Descriptions of New Ophiuridae, belonging to the Smithsonian Institution and to the Museum of Comparative Zoology at Cambridge. Proceedings of the Boston Society of Natural History, 7, 193 - 204 + 252 - 262. https: // doi. org / 10.5962 / bhl. part. 4822","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Nielsen, E. (1932) Ophiurans from the Gulf of Panama, California and the Strait of Georgia. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening, 91, 241 - 346.","Fell, B. H. (1962) A revision of the major genera of Amphiuroid Ophiuroidea. Transactions of the Royal Society of New Zealand, Zoology, 2 (2), 1 - 26.","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Granja-Fernandez, R., Maya-Alvarado, B., Cupul-Magana, A. L., Rodriguez-Troncoso, A. P., Solis-Marin, F. A. & Sotelo-Casas, R. S. (2021) Echinoderms (Echinodermata) from the Central Mexican Pacific. Revista de Biologia Tropical, 69 (S 1), 219 - 253. https: // doi. org / 10.15517 / rbt. v 69 iSuppl. 1.46356","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306."]}

Amphiura (Amphiura) diomedeae Lütken & Mortensen, 1899 Fig. 15G‒L Amphiura diomedeae Lütken & Mortensen, 1899: 151‒152, pl. 12, figs. 1‒7.— H.L. Clark 1911: 140‒141; 1917: 436‒437.— Koehler 1922: 158‒159, pl. 67, figs. 7‒10.— Hendler 1996: 147‒149, fig. 7.12.— Lambert & Boutillier 2011: 53. Amphiura (Amphiura) diomedeae. Cherbonnier & Guille 1978: 35‒36, fig. 10. See Hendler (1996) for other synonymous records. Material examined. 40 individuals at 10 stations. TALUD IV, Sta. 25, 4 ind. (ICML-EMU-11151-A). TALUD VIII, Sta. 15, 1 ind. (ICML-EMU-11151-B). TALUD XII, Sta. 13, 4 ind. (ICML-EMU-11152); Sta. 25, 1 ind. (ICML-EMU-11696); Sta. 26, 3 ind. (ICML-EMU-11157). TALUD XIV, Sta. 15, 1 ind. (ICML-EMU-11665). TALUD XVIB, Sta. 1, 1 ind. (ICML-EMU-11153); Sta. 5, 1 ind. (ICML-EMU-11156-A); Sta. 22, 6 ind. (ICML-EMU-11154) and 3 ind. (ICML-EMU-11156-B); Sta. 27, 15 ind. (ICML-EMU-11155). Comparative material. Syntypes, 9 ind.: MCZ OPH-1305, MCZ OPH-1379 (Supplementary file 2). Description (ICML-EMU-11155). DD = 12 mm. Disc interradially incised. Dorsal disc covered by imbricated scales, center scales larger. Primary plates oval, separated from each other by scales. RS triangular, in contact or slightly in contact only distally, the rest separated by scales (Fig. 15G). Ventral interradii covered by imbricated scales, smaller than dorsal scales (Fig. 15H). OSh broader than long, diamond-shaped with rounded edges. Madreporite larger than OSh, with about five hydropores. AdSh scalene triangular, separated. Jaws bearing four oral papillae at each side; AdShSp and 2AdShSp rounded, short; BSc pointed, short; IPa rounded; a gap between BSc and IPa. vT quadrangular (Fig. 15I). Arms slender. DAP broader than long, widely fan-shaped, contiguous (Fig. 15J). VAP almost as broad as long, pentagonal, slightly separated from each other. LAP with up to three ArSp, elongated (almost two arm segments in length), pointed, middle the longest, dorsalmost the shortest and most slender. Tentacle pores with two oval TSc (Fig. 15K). Color pattern dorsally and ventrally light brown (ethanol preservation) (Fig. 15G‒L). Habitat and distribution. Sri Lanka, Maldives, Philippines Islands, Japan, Tahiti, USA, Mexico, Costa Rica, Panama, Ecuador, and Peru (Lütken & Mortensen 1899; H.L. Clark 1911, 1917; Koehler 1922; Hendler 1996; Stöhr & O’Hara 2021); 71‒ 3,310 m depth (Hendler 1996; Stöhr & O’Hara 2021), sandy and rocky substrates (Lütken & Mortensen 1899). The material examined was collected from off western Baja California, in the Gulf of California, and off Colima and Guerrero; 772‒ 2,054 m depth. Remarks. Despite its wide geographical distribution, Amphiura (Amphiura) diomedae had previously been recorded in Mexico only in the Gulf of California (Granja-Fernández et al. 2015). The new records off western Baja California, Colima, and Guerrero indicates a much wider distribution range in western Mexico than previously thought., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 50-51, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Koehler, R. (1922) Ophiurans of the Philippine Seas and adjacent waters. Bulletin of the United States National Museum, 100, 1 - 486. https: // doi. org / 10.5962 / bhl. title. 32917","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140.","Cherbonnier G. & Guille, A. (1978) Faune de Madagascar: Ophiurides. Vol. 48. Museum national d'Histoire naturelle, Paris, 272 pp.","Stohr, S. & O'Hara, T. D. (2021) Deep-sea Ophiuroidea (Echinodermata) from the Danish Galathea II Expedition, 1950 - 52, with taxonomic revisions. Zootaxa, 4963 (3), 505 - 529. https: // doi. org / 10.11646 / zootaxa. 4963.3.6","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Ophiacantha costata Lütken & Mortensen, 1899 Fig. 8A‒F Ophiacantha costata Lütken & Mortensen, 1899: 172‒173, pl. 16, fig. 10, pl. 17, figs. 4‒6. Material examined. Two individuals at two stations. TALUD VIII, Sta. 11, 1 ind. (ICML-EMU-11695); TALUD XII, Sta. 28, 1 ind. (ICML-EMU-11700). Comparative material. Syntypes, 9 ind.: MCZ OPH-1941, MNHN 2013-10259, USNM 19573, USNM 19574 (Supplementary file 2). Description (ICML-EMU-11700). DD = 6 mm. Disc interadii deeply indented. Dorsal disc covered by scales and short multifid spines. Primary plates not evident. RS slender, elongated, covered by multifid spines (Fig. 8A). Ventral interradii very reduced, covered by imbricated scales and spines similar to those on the dorsal side (Fig. 8B). OSh broader than long, diamond-shape with distal rounded edge. Madreporite swollen. AdSh longer than broad, semilunar; almost meeting or meeting in front of OSh. Jaws bearing five papillae at each side; AdShSp lanceolate; LOPa three, lanceolate, first the longest of all oral papillae, the rest slender; IPa pointed. vT longer than oral papillae (Fig. 8C). Arms slender, gradually narrowing distally. First DAP reduced, covered by short multifid spines; subsequent DAP slightly longer than broad, bell-shaped with rounded edges; separated from each other by lateral plates (Fig. 8D). VAP broader than long, pentagonal, separated from each other. LAP with six ArSp, large (approximately 1.5 arm segment in length), serrated, dorsalmost the longest and ventralmost the shortest. One elongated, pointed TSc (Fig. 8E). Color pattern beige (ethanol preservation) (Fig. 8A‒F). Habitat and distribution. California, USA, Mexico, and Panama; 733‒ 1,271 m depth, sandy substrates (Lütken & Mortensen 1899; Maluf 1988). The material examined was collected in the southern Gulf of California and off Colima; 920‒ 1,106 m depth. Remarks. The widely open genital slits (Fig. 8B) in our examined material can be an artifact of preservation or a stress reaction to the fixing process (pers. comm. Sabine Stöhr, 2022). Previously recorded in the Gulf of California and off Marias Islands (Granja-Fernández et al. 2015). The examined material collected off Colima corresponds to a new distribution record for this area and the southernmost record in the Mexican Pacific.

Amphiura gymnogastra Lütken & Mortensen, 1899 Fig. 15A‒F Amphiura gymnogastra Lütken & Mortensen, 1899: 145‒146, pl. 9, figs. 6‒8.— H.L. Clark 1917: 437. Hemilepis gymnogastra. Fell 1962: 10, 22. Material examined. Four individuals at two stations. TALUD XII, Sta. 13, 3 ind. (ICML-EMU-11148-A); Sta. 26, 1 ind. (ICML-EMU-11148-B). Comparative material. Syntypes, 5 ind.: MCZ OPH-1321, USNM 19526 (Supplementary file 2). Description (ICML-EMU-11148-A). DD = 6.6 mm. Disc malformed. Dorsal disc covered by imbricated scales, those surrounding RS larger, integument distally. Primary plates not evident. RS triangular with rounded edges, prominent distal end, in contact only distally, the rest separated by scales (Fig. 15A). Ventral interradii covered by scale-less integument (Fig. 15B). OSh broader than long, spearhead-shaped with strongly convex proximal and lateral edges and distal lobe. Madreporite rounder and larger than OSh. AdSh scalene triangular, separated. Jaws bearing three oral papillae at each side; AdShSp scale-like round; BSc slender, pointed; IPa quadrangular with rounded edges. vT quadrangular (Fig. 15C). Arms slender. DAP broader than long, oval, contiguous (Fig. 15D). VAP longer than broad, pentagonal, contiguous. LAP with 5‒6 ArSp, small (approximately 1.2 arm segment in length), conical with blunt tip; ventralmost the longest, dorsalmost the thinnest and shortest. Tentacle pores with two oval TSc, adradial longer (Fig. 15E). Color pattern in dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 15A‒F). Habitat and distribution. Mexico, Panama, and the Galapagos Islands; 549‒ 2,323 m depth, hard and muddy substrates (Lütken & Mortensen 1899; H.L. Clark 1911; Maluf 1988; see Remarks). The material examined was collected off Colima and Guerrero; 1,199 ‒1,956 m depth. Remarks. Specimens of Amphiura gymnogastra tend to lose their disc and oral papillae very easily, thus making correct identification very complicated. This species can have a dorsal disc covered with imbricated scales or with scales and small areas near the margin of the disc with only integument.Areas with integument in the dorsal disc can result from the pressure by the ventral disc on the dorsal side during the sampling process. Amphiura gymnogastra has been previously recorded off Panama and the Galapagos Islands (Lütken & Mortensen 1899; H.L. Clark 1911), and records off central and southern Mexico represent a significant extension of its northernmost distribution limit to 18º33′27″N, 104º28′21″W. Available material of A. gymnogastra is currently limited to 13 specimens: 1) the type material, which is not in good condition (MCZ OPH-1321, two specimens; USNM 19526, three specimens), 2) one lot from the Galapagos Islands (USNM E669, four specimens), and 3) two lots from the TALUD cruises (ICML -EMU-11148-A, three specimens; ICML-EMU-11148-B, one specimen).

Ophiopholis longispina H.L. Clark, 1911 Fig. 19A‒F Ophiopholis longispina H.L. Clark, 1911: 116, 119‒121, fig. 45.— Kyte 1969a: 1732, 1738.— Lambert & Austin 2007: 110, 118‒119, figs. 67‒68. Material examined. 5,232 individuals at nine stations. TALUD VIII, Sta. 11, 2 ind. (ICML-EMU-11051-A) and 17 ind. (ICML-EMU-11051-B). TALUD X, Sta. 4, 1 ind. (ICML-EMU-11045-B) and 9 ind. (ICML-EMU-11045-C); Sta. 5, 4 ind. (ICML-EMU-11045-A). TALUD XIV, Sta. 4, 7 ind. (ICML-EMU-11052-A); Sta. 8, 5 ind. (ICML-EMU-11052-B). TALUD XV, Sta. 5D, 4 ind. (ICML-EMU-11050); Sta. 20, 1 ind. (ICML-EMU-11048-A) and 13 ind. (ICML-EMU-11048-B); Sta. 23, 268 ind. (ICML-EMU-11046), 3 ind. (ICML-EMU-11047-A), 1 ind. (ICML-EMU-11047-B), 1 ind. (ICML-EMU-11047-C), 4 ind. (ICML-EMU-11049-B), 4,841 ind. (ICML-EMU-11222), 6 ind. (ICML-EMU-11687), 1 ind. (ICML-EMU-12999), and 1 ind. (ICML-EMU-11049-A). TALUD XVIB, Sta. 5, 36 ind. (ICML-EMU-11044) and 7 ind. (ICML-EMU-11053). Comparative material. Holotype: USNM 25653. Paratypes, 49 ind.: MCZ OPH-3126, MCZ OPH-3406, USNM 26006, USNM 26089, USNM 26132, USNM 26611, USNM 27047 (Supplementary file 2). Description (ICML-EMU-11044). DD = 8.7 mm. Disc round. Dorsal disc covered by scales and long spines, more numerous marginally. Primary plates not evident. RS scalene triangular, without spines, separated by scales and spines, except distally (Fig. 19A). Ventral interradii covered by scales and some short spines (Fig. 19B). OSh broader than long, diamond-shaped with rounded edges. Madreporite larger and rounder than OSh. AdSh curved, separated in front of OSh. Jaws bearing numerous oral papillae; one AdShSp elongated; one 2AdShSp elongated; LOPa 1‒2 elongated; TPas numerous, clustering, short. vT rectangular (Fig. 19C). Arms slender. DAP longer than broad, oval, surrounded by small oval plates, contiguous (Fig. 19D). VAP longer than broad, pentagonal, separated. LAP with up to 6‒7 ArSp, blunt tip, serrated, elongated (approximately two arm segments in length), dorsalmost the longest, ventralmost the shortest, distalmost arm spines hooked, hyaline. Tentacle pores with one oval TSc (Fig. 19E). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 19A‒F). Habitat and distribution. Canada, USA, and northern Mexico; 51‒ 1,746 m depth, on sponges, gorgonians, and muddy substrates (H.L. Clark 1911; Maluf 1988; Lambert & Austin 2007; Granja-Fernández et al. 2015). The material examined was collected off western Baja California and Baja California Sur, and in the Gulf of California; 435‒920 m depth, on gorgonians. Remarks. Some variations were observed among specimens examined herein: different densities of spines on the dorsal disc, rounded and rosaceous dorsal arm plates, the shape of the jaw, and the first ventral segments of the arms can be grooved in larger specimens. These variations could be related to size, but further analysis is needed to confirm it. The oral papillae are easily removable from the jaw; therefore, many specimens have a jaw with an ophiotrichid appearance. The record from off western Baja California is new., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 60, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Ophiolimna phragma (Ziesenhenne, 1940) new combination Fig. 11G‒L Ophiacantha phragma Ziesenhenne, 1940: 11‒13, pl. 2 figs. 4‒6.— Boolotian & Leighton 1966: 7, 10, fig. 29. Material examined. One individual at one station. TALUD XVIB, Sta. 28, 1 ind. (ICML-EMU-11682). Comparative material. Ophiacantha phragma Ziesenhenne, 1940, holotype, 1 ind.: LACM 597.7. Paratypes, 23 ind.: LACM 597.3, LACM 597.6, LACM 597.8, LACM 597.9, LACM 597.10, LACM 597.11, LACM 597.12, LACM 597.13, LACM 597.14, LACM 597.15, LACM 597.16 (Supplementary file 2). Description (ICML-EMU-11682). DD = 6 mm. Disc rounded. Dorsal disc densely covered by granules and scattered elongated spines. Primary plates not evident. RS covered by granules and spines (Fig. 11G). Ventral interradii covered by granules, smaller than dorsal granules (Fig. 11H). OSh broader than long, triangular with rounded edges, granules distally. Madreporite larger than OSh, with a central rounded depression. AdSh longer than broad, very slender, meeting in front of OSh. Jaws bearing 5‒6 papillae at each side; AdShSp rounded; LOPa 3‒4, first LOPa similar in shape to AdShSp but smaller, rest elongated and pointed; IPa elongated, pointed. vT wider than oral papillae (Fig. 11I). Arms slender. First DAP covered by granules; subsequent DAP longer than broad, hexagonal with rounded distal edge, meeting. Longitudinal swollen keel along DAP (Fig. 11J). First VAP broader than long, rhombic, smaller than rest. Second to fourth VAP broader than long; subsequent VAP longer than broad, triangular with concave distal edge, meeting excepting distally. LAP striated. LAP with 6‒7 ArSp, large (almost two arm segments in length), slender, blunt, dorsalmost largest, ventralmost shortest. First 2‒3 tentacle pores with two TSc; subsequent pores with one oval TSc (Fig. 11K). Color pattern in dorsal disc and arms brown (Fig. 11G, J, L), ventral side beige (ethanol preservation) (Fig. 11H). Habitat and distribution. California, USA, Mexico, Costa Rica, Panama, Colombia, Ecuador, and the Galapagos Islands; 13‒ 1,532 m depth, muddy and sandy substrates, gravel, and coralline bottoms (Ziesenhenne 1940; Solís-Marín et al. 2013; see Remarks). The material examined was collected off western Baja California; 1,461 ‒1,532 m depth. Remarks. The genus Ophiacantha is characterized by uncovered bar-like radial shields (Matsumoto 1917), but Ophiacantha phragma, as originally described, has radial shields covered by granules and spines. Our revision of O. phragma, including a detailed examination of the holotype and paratypes, clearly indicated that it belongs to Ophiolimna due to the following characters: 1) a disc densely covered with numerous granules and few spines, 2) distalmost papillae broad, rounded, and operculiform, 3) the junction area of the adoral shields and the edges of the oral shield covered by granules, 4) a single broad tentacle scale, and 5) striated lateral arm plates (O’Hara & Stöhr 2006; Martynov 2010). Therefore, it is herein proposed to assign this species to the genus Ophiolimna (new combination). Ophiolimna phragma is very similar to O. bairdi, but the following characteristics help to easily distinguish them from one another (comparing specimens with a similar size, DD = 6 mm): 1) dorsal arm plates triangular, as long as wide in O. bairdi vs. hexagonal, longer than wide (2‒3 times) in O. phragma, 2) adoral shields conspicuous in O. bairdi vs. inconspicuous, hardly noticeable in O. phragma, 3) distalmost oral papilla of much larger size in O. bairdi, and 4) one tentacle scale in O. bairdi vs. first 1‒8 segments with two tentacle scales and then with one tentacle scale in O. phragma. The genus Ophiolimna currently includes seven species (Stöhr et al. 2022) of which O. bairdi and O. phragma are the two representatives for the eastern tropical Pacific. The previously deepest record for O. phragma was from 644 m depth (Maluf 1988; as Ophiacantha phragma), but during the TALUD cruises one specimen was collected as deep as 1,532 m., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 40-42, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Ziesenhenne, F. C. (1940) New Ophiurans of the Allan Hancock Pacific Expeditions. Allan Hancock Pacific Expeditions, 8 (2), 9 - 52.","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Lyman, T. (1883) Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Caribbean Sea (1878 - 79), and on the east coast of the United States, during the summer of 1880, by the U. S. coast survey steamer \" Blake \", commander J. R. Bartlett, U. S. N., commanding. XX. Report on the Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 10 (6), 227 - 287.","Solis-Marin, F. A., Alvarado, J. J., Abreu-Perez, M., Aguilera, O., Ali, J., Bacallado-Aranega, J. J., Barraza, E., Benavides-Serrato, M., Benitez-Villalobos, F., Betancourt-Fernandez, L., Borges, M., Brandt, M., Brogger, M. I., Borrero-Perez, G. H., Buitron- Sanchez, B. E., Campos, L. S., Cantera, J., Clemente, S., Cohen-Renjifo, M., Coppard, S., Costa-Lotufo, L. V., del Valle- Garcia, R., Diaz, Y., Diaz de Vivar, M. E., Diaz-Martinez, J. P., Duran-Gonzales, A., Ephera, L., Escolar, M., Francisco, V., Freire, C. A., Garcia-Arraras, J. E., Gil, D. G., Hadel, V. F., Hearn, A., Hernandez, J. C., Hernandez-Delgado, E. A., Herrera- Moreno, A., Herrero-Perezrul, M. D., Hooker, Y., Honey-Escandon, M. B. I., Lodeiros, C., Luzuriaga, M., Manso, C. L. C., Martin, A., Martinez, M. I., Martinez, S., Moro-Abad, L., Mutschke, E., Navarro, J. C., Neira, R., Noriega, N., Palleiro- Nayar, J. S., Perez, A. F., Perez-Ruzfa, A., Prieto-Rios, E., Reyes, J., Rodriguez, R., Rubilar, T., Sancho-Mejia, T., Sangil, C., Silva, J. R. M. C., Sonnenholzner, J. I., Ventura, C. R., Tablado, A., Tavares, Y., Tiago, C. G., Tuya, F. & Williams, S. M. (2013) Appendix. In: Alvarado-Barrientos, J. J. & Solis-Marin, F. A. (Eds.), Echinoderm research and diversity in Latin America. Springer-Verlag, Berlin, pp. 543 - 658.","Matsumoto, H. (1917) A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo, 32 (2), 1 - 408.","O'Hara, T. D. & Stohr, S. (2006) Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Forges, R. & Justine, J. L. (Eds.), Tropical deep-sea benthos. Vol. 24. Memoires du Museum national d´Histoire naturelle, Paris, 193, pp. 33 - 141.","Martynov, A. (2010) Reassessment of the classification of the Ophiuroidea (Echinodermata), based on morphological characters. I. General character evaluation and delineation of the families Ophiomyxidae and Ophiacanthidae. Zootaxa, 2697 (1), 1 - 154. https: // doi. org / 10.11646 / zootaxa. 2697.1.1","Stohr, S., O'Hara, T. & Thuy, B. (2022) World Ophiuroidea database. Available from: http: // marinespecies. org / aphia. php? p = search (accessed 15 April 2022)","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306."]}

Ophiopholis bakeri McClendon, 1909 Fig. 18G‒L Ophiopholis bakeri McClendon, 1909: 41, pl. 5, figs. 26‒27.— H.L. Clark 1911: 121‒123, fig. 46.— Ziesenhenne 1937: 224.— Boolotian & Leighton 1966: 7‒8, fig. 28.— Kyte 1969a: 1729, 1732, 1738.— Hendler 1996: 157‒159, fig. 7.17.— Lambert & Austin 2007: 110, 113‒114, figs. 62‒63. See Hendler (1996) for other synonymous records. Material examined. 150 individuals at three stations. TALUD XIV, Sta. 4, 2 ind. (ICML-EMU-11043-B); Sta. 10, 10 ind. (ICML-EMU-13003); Sta. 15, 1 ind. (ICML-EMU-11043-A); Sta. 20, 22 ind. (ICML-EMU-11042-B), 87 ind. (ICML-EMU-11041), and 10 ind. (ICML-EMU-11042-A). TALUD XV, Sta. 23, 18 ind. (ICML-EMU-11043-C). Comparative material. MCZ OPH-7061, 2 ind (Supplementary file 2). Material identified by McClendon. The lot MCZ OPH-7061 deposited at the MCZ has a label with the legend: “Univ. Calif. Dep. Zool. Type?”. However, it does not have any additional information (e.g., locality, collection date) or any other note suggesting that it is, in fact, the type material of O. bakeri. McClendon, who originally described the species (McClendon 1909), is actually the person who identified lot MCZ OPH-7061 (pers. comm. Penny Benson 2016). According to McClendon (1909), the type material of O. jolliense was deposited at the University of California Museum but despite an exhaustive search for this material, we did not locate it in this museum (pers. comm. Erica Clites & Carole Hickman 2018) or in any other institution (i.e., LACM, MCZ, NHMD, USNM; pers. comm. Penny Benson 2016, Rich Mooi 2018). Lot MCZ OPH-7061 might have been sent to MCZ as a loan or a gift. Description (ICML-EMU-11041). DD = 8 mm. Disc round, weakly indented interradially. Dorsal disc covered by scales and short multifid spines, marginal and central spines elongated. Primary plates not evident. RS scalene triangular, covered by multifid spines (often shorter than on other parts of the disc), separated by scales and multifid spines, except distally (Fig. 18G). Ventral interradii covered by elongated multifid spines (Fig. 18H). OSh broader than long, diamond-shaped. Madreporite larger and rounder than OSh.AdSh curved, separated in front of OSh. Jaws bearing numerous oral papillae; one AdShSp rounded; one 2AdShSp oblong, the longest; LOPa 1‒2 oblong; TPas numerous, clustering, short. vT rectangular (Fig. 18I). Arms slender. DAP as broad as long, rounded, surrounded by rounded symmetrical plates, contiguous (Fig. 18J). VAP longer than broad, pentagonal, separated.LAP with up to 4‒5 ArSp, blunt tip, serrated, elongated (approximately two arm segments in length), some first dorsalmost rudimentary, second dorsalmost the longest, ventralmost the shortest, distalmost arm spines hooked, hyaline. Tentacle pores with one oval TSc (Fig. 18K). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 18G‒L). Habitat and distribution. British Columbia, Canada, Washington, Oregon, and California, USA, and northern Mexican Pacific; 18‒ 1,204 m depth, coral, sponges, rocky, sandy, and muddy substrates (McClendon 1909; H.L. Clark 1911; Hendler 1996; Lambert & Austin 2007; Granja-Fernández et al. 2015). The material examined was collected off western Baja California Sur and in the northern Gulf of California; 325‒871 m depth, associated with sponges. Remarks. Many of the ethanol preserved specimens had dorsally and ventrally beige-whitish coloration. Nevertheless, we also observed that some preserved specimens displayed a rosaceous or brown coloration. This species is known to display a wide variety of colors: pink, red, gray, and yellowish-white (Hendler 1996; Lambert & Austin 2007). Moreover, multifid spines in the center of the disc can be present or not, and some specimens can have up to six arm spines. The Ophiopholis species distributed in the eastern tropical Pacific (northern Mexico) are Ophiopholis bakeri and Ophiopholis longispina, which differentiate by: 1) dorsal disc covered with scales and short multifid spines in O. bakeri vs. covered with scales and long spines in O. longispina, 2) RS covered with multifid spines in O. bakeri vs. RS without spines in O. longispina, and 3) LAP with up to 4‒5 ArSp, some first dorsalmost rudimentary, second dorsalmost the longest in O. bakeri vs. up to 6‒7 ArSp, first dorsalmost the longest in O. longispina. On the other hand, Ophiopholis aculeata (Linnaeus, 1767) and Ophiopholis kennerlyi Lyman, 1860 have been reported from the North Pacific and differ from O. bakeri by their granule-covered dorsal disc and their angular accessory arm plates (Lambert & Austin 2007)., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 58-60, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Ziesenhenne, F. C. (1937) The Templeton Crocker Expedition. X. Echinoderms from the West Coast of Lower California, the Gulf of California and Clarion Island. Zoologica, 22 (15), 209 - 239. https: // doi. org / 10.5962 / p. 184686","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Lyman, T. (1875) II. Ophiuridae and Astrophytidae. Zoological results of the \" Hassler \" Expedition. Illustrated Catalogue of the Museum of Comparative Zoology at Harvard College, 8, 1 - 34.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Linnaeus, C. (1767) Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis., Vol I. Laurentii Salvii, Stockholm, 794 pp. https: // doi. org / 10.5962 / bhl. title. 156772","Lyman, T. (1860) Descriptions of New Ophiuridae, belonging to the Smithsonian Institution and to the Museum of Comparative Zoology at Cambridge. Proceedings of the Boston Society of Natural History, 7, 193 - 204 + 252 - 262. https: // doi. org / 10.5962 / bhl. part. 4822"]}

Dougaloplus sp. Fig. 17A‒F Material examined. 24 individuals at eight stations. TALUD IV, Sta. 19, 1 ind. (ICML-EMU-11158-A); Sta. 25, 1 ind. (ICML-EMU-11158-B). TALUD VII, Sta. 19, 9 ind. (ICML-EMU-9014-A) and 1 ind. (ICML-EMU-9014-B). TALUD VIII, Sta. 3, 1 ind. (ICML-EMU-11159-A); Sta. 20, 4 ind. (ICML-EMU-11159-B) and 4 ind. (ICML-EMU-11670). TALUD IX, Sta. 4, 1 ind. (ICML-EMU-11160-A); Sta. 21B, 1 ind. (ICML-EMU-11160-B). TALUD XII, Sta. 13, 1 ind. (ICML-EMU-11161). Comparative material. Amphilimna pentacantha H.L. Clark, 1911 (junior synonym of Dougaloplus amphacanthus (McClendon, 1909)), holotype: USNM 25614. Paratypes, 10 ind.: MCZ OPH- 3172, MCZ OPH- 3384. Amphioplus hexacanthus H.L. Clark, 1911 (junior synonym of Dougaloplus amphacanthus (McClendon, 1909)), syntype, 1 ind.: MCZ OPH- 3169. Amphiura notacantha Lütken & Mortensen, 1899 (original name of Dougaloplus notacanthus (Lütken & Mortensen, 1899), holotype: USNM 19543 (Supplementary file 2). Description (ICML-EMU-9014-A). DD = 7 mm. Disc malformed. Dorsal disc covered by imbricated scales, largest in the center, and by pointed spines on interradius and RS. Primary plates not evident. RS bar-like, elongated and narrow, meeting distally, separated by scales except distally (Fig. 17A). Ventral interradii covered by scales smaller than dorsal disc (Fig. 17B). OSh broader than long, rounded pentagonal, distal edge concave. Madreporite slightly larger than OSh. AdSh scalene triangular, separated. Jaws bearing four oral papillae at each side; AdShSp rounded, the shortest; 2AdShSp pointed; BSc pointed; IPa quadrangular-rounded. vT quadrangular (Fig. 17C). Arms slender. DAP broader than long, widely oval, separated from each other (Fig. 17D). VAP longer than broad, pentagonal, slightly separated from each other. Up to five ArSp, small (approximately one arm segment in length), pointed, ventralmost the longest, dorsalmost the shortest. Tentacle pores with one round TSc (Fig. 17E). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 17A‒F). Habitat and distribution. The material examined was collected in the southern Gulf of California and off Guerrero; 778‒ 1,395 m depth. Remarks. The genus Dougaloplus is represented in eastern tropical Pacific by three species: Dougaloplus amphacanthus (McClendon, 1909), Dougaloplus gastracanthus (Lütken & Mortensen, 1899), and Dougaloplus notacanthus (Lütken & Mortensen, 1899). Compared with the material of Dougaloplus sp. examined, D. amphacanthus is characterized by a dorsal disc densely covered with spines, two tentacle scales, and a bifurcated tip on the arm spines. Dougaloplus sp. is close to D. gastracanthus and D. notacanthus (which are very similar in appearance), but these two species differ from our material in having less spines on the dorsal disc, and the elongated and pointed oral papillae. Information and material of D. gastracanthus and D. notacanthus are restricted to the original description of D. gastracanthus (Lütken & Mortensen 1899) and the damaged holotype of D. notacanthus; additional, non-type material of these two species is not available. More specimens of these species are needed to elucidate whether Dougaloplus sp. belongs to either D. gastracanthus or D. notacanthus, or if it belongs to a new species., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 55, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208."]}

Key to the identification of the genera and species of deep-sea Ophiuroidea collected during the TALUD cruises in western Mexico 1 Dorsal disc with naked skin and external ossicles. DAP and VAP absent......................................... 2 1’ Dorsal disc without naked skin and external ossicles. DAP and VAP present...................................... 4 2 Up to 3–4 ArSp, serrated but not hooked............... genus Astrodia, Astrodia excavata (Lütken & Mortensen, 1899) 2’ More than three ArSp, modified as hooks................................................... genus Asteronyx, 3 3 Ventral interradii with some granule-shaped epidermal ossicles proximally. Genital slits oval, restricted to middle-distal part of the interradius, covering approximately 3/4 of the interradius. OSh rounded triangular. Madreporite not evident. Oral papillae spiniform............................................................. Asteronyx longifissus Döderlein, 1927 3’ Ventral interradii with circular-shaped epidermal ossicles. Genital slits round, restricted to proximal part of the interradius, covering approximately 1/6 of interradius. OSh not evident. One small circular madreporite. Oral papillae granule-like....................................................................... Asteronyx loveni Müller & Troschel, 1842 4 Dorsal disc with disc scales, obscured by skin and covered with fine granules.......................................................................... genus Ophiernus, Ophiernus adspersus annectens Lütken & Mortensen, 1899 4’ Dorsal disc with scales, visible and not obscured by skin...................................................... 5 5 Dorsal disc with scales only............................................................................ 6 5’ Dorsal disc with scales and granules, spines............................................................... 24 6 Dorsal disc scales depressed............................. genus Histampica, Histampica cf. duplicata (Lyman, 1875) 6’ Dorsal disc scales not depressed......................................................................... 7 7 Jaws bearing more than three oral papillae at each side....................................................... 8 7’ Jaws bearing three oral papillae at each side............................................................... 19 8 Dorsal disc with diminutive scales, naked appearance........................................................ 9 8’ Dorsal disc with scales, appearance not naked............................................................. 10 9 Jaws bearing 6–7 oral papillae at each side, distalmost lanceolate and the largest. Up to three ArSp, approximately two arm segments in length. Two TSc, adradial slender and elongated, abradial rounded........................................................................................ genus Ophiochiton, Ophiochiton cf. fastigatus Lyman, 1878 9’ Jaws bearing 2–3 oval AdShSp and 2AdShSp, BSc elongated, TPa numerous, elongated, different sizes. Up to five ArSp, approximately one arm segment in length. Two TSc, adradial lanceolate and extremely elongated crossing the abradial TSc, abradial pointed....................................... genus Ophiopsila, Ophiopsila californica A.H. Clark, 1921 10 Few pairs of tentacle pores, restricted to proximal arm segments. Arm combs absent............................... 11 10’ Numerous pairs of tentacle pores, present in most arm segments. Arm combs present.............................. 14 11 Tentacle pores obvious on two proximal arm segments... genus Ophiomusa, Ophiomusa lymani (Wyville-Thomson, 1873) 11’ Tentacle pores obvious on three or more proximal arm segments........................... genus Ophiosphalma, 12 12 Tentacle pores obvious on up to 3–5 proximal arm segments. One pointed abradial and 1–2 adradial TSc. Up to 12 ArSp............................................................ Ophiosphalma glabrum (Lütken & Mortensen, 1899) 12’ Tentacle pores obvious on up to three proximal arm segments. One round TSc. Up to three ArSp..................... 13 13 Primary plates round, conspicuous. RS covering 1/3 of the disc radius. OS spearhead-shaped, rounded angles............................................................................ Ophiosphalma jolliense (McClendon, 1909) 13’ Primary plates not conspicuous. RS covering 1/2 of the disc radius. OS rhomboidal-shaped, right angles......................................................................... Ophiosphalma variabile (Lütken & Mortensen, 1899) 14 Disc rounded....................................................................................... 15 14’ Disc pentagonal..................................................................................... 17 15 Rays of integument in RS and project from the arms................. genus Ophiura, Ophiura flagellata (Lyman, 1878) 15’ Center of the disc without interradial rays of integument..................................................... 16 16 RS triangular. VAP almost hemispherical, widely separated. Genital papillae pointed. Jaws bearing four oral papillae at each side, IPa rectangular, 2IPa semi-oval. Three ArSp. First tentacle pore with 1–2 oval TSc....................................................................................... genus Ophiocten, Ophiocten hastatum Lyman, 1878 16’ RS shields oval. VAP diamond-shaped, separated. Genital papillae papilliform. Jaws bearing 6–7 oral papillae at each side, IPa semi-rectangular, 2IPa semi-quadrangular. 3–4 ArSp. First tentacle pore with 8–9 elongated TSc................................................................. genus Ophiuroglypha, Ophiuroglypha irrorata irrorata (Lyman, 1878) 17 RS tuberculous, very swollen. DAP with a prominent longitudinal keel............................................................................................... genus Stegophiura, Stegophiura ponderosa (Lyman, 1878) 17’ RS not tuberculous and not swollen. DAP without a prominent longitudinal keel............... genus Amphiophiura, 18 18 Disc with a central depression, covered with irregular oval scales. Primary plates conspicuous. Genital papillae minute, pointed. Arm combs with rounded papillae. Jaws bearing five oral papillae at each side, TPa two. Three ArSp, pointed often widened at the tip........................................................... Amphiophiura oligopora (H.L. Clark, 1913) 18’ Disc swollen without a central depression, covered with irregular, prominent, inflated right-angled plates. Primary plates not conspicuous. Genital papillae small, quadrangular.Arm combs with pointed or rounded-squared papillae. Jaws bearing 4–5 oral papillae at each side, TPa 1–2. 3–4 blunt ArSp.................... Amphiophiura superba (Lütken & Mortensen, 1899) 19 Ventral interradius covered with granules.................................................................................................... genus Amphichondrius, Amphichondrius granulatus (Lütken & Mortensen, 1899) 19’ Ventral interradius covered with scales/integument......................................................... 20 20 AdShSp larger than all other oral papillae. BSc absent......... genus Amphipholis, Amphipholis pugetana (Lyman, 1860) 20’ AdShSp same size as all other oral papillae. BSc present...................................... genus Amphiura, 21 21 One TSc.............................................................. Amphiura carchara H.L. Clark, 1911 21’ Two TSc........................................................................................... 22 22 Dorsal disc only with scales. Ventral interradius with imbricated scales. Primary plates conspicuous...................................................................... Amphiura (Amphiura) diomedeae Lütken & Mortensen, 1899 22’ Dorsal disc with thickened integument and scales. Ventral interradii with thickened integument. Primary plates inconspicuous.................................................................................................. 23 23 Dorsal disc mostly only with integument, imbricating scales only around RS. Up to 6–7 flat tipped ArSp...................................................................................... Amphiura arcystata H.L. Clark, 1911 23’ Dorsal disc with integument only distally, imbricated scales on most of disc. Up to 5–6 blunt tip ArSp............................................................................ Amphiura gymnogastra Lütken & Mortensen, 1899 24 Dorsal disc with scales, spines and/or granules............................................................. 25 24’ Dorsal disc with scales and spines....................................................................... 30 25 Dorsal disc with scales and granules. Without striated LAP................................................... 26 25’ Dorsal disc with scales, granules, and spines. With striated LAP............................... genus Ophiolimna, 29 26 Detached granules on dorsal disc leave a fingerprint as a depression in each scale when the specimens are roughly handled............................................. genus Ophiomitra, Ophiomitra granifera Lütken & Mortensen, 1899 26’ Detached granules on dorsal disc do not leave a fingerprint as a depression in each scale when the specimens are roughly handled......................................................... genus Ophiophthalmus and Ophiacantha, 27 27 Distal edge of DAP with a conspicuous row of pointed granules............... Ophiophthalmus normani (Lyman, 1879) 27’ Distal edge of DAP without a conspicuous row of pointed granules............................................ 28 28 Jaws bearing six oral papillae at each side, AdShSp elongated. 6–7 smooth ArSp. Two oval TSc........................................................................................... Ophiacantha diplasia H.L. Clark, 1911 28’ Jaws bearing 6–7 oral papillae at each side, AdShSp rounded. Up to 4–5 smooth, flattened ArSp. First seven tentacle pores with two TSc, subsequent pores with one lanceolate TSc...................... Ophiacantha quadrispina (H.L. Clark, 1917) 29 Jaws bearing five oral papillae at each side, one IPa. DAP triangular. Up to 7–8 smooth, pointed ArSp. One lanceolate TSc......................................................................... Ophiolimna bairdi (Lyman, 1883) 29’ Jaws bearing 5–6 oral papillae at each side, two IPa. DAP hexagonal. Up to 6–7 slender, blunt ArSp. First 2–3 tentacle pores with two TSc, subsequent pores with one oval TSc........................ Ophiolimna phragma (Ziesenhenne, 1940) 30 TPas absent........................................................................................ 31 30’ TPas present as cluster................................................................................ 36 31’ One or no papilla ventral to teeth...................................................... genus Ophiacantha, 32 31’ Two oral papillae (IPa) at the apex of jaw, ventral to teeth.................................................... 35 32 Arms with noded appearance................................ Ophiacantha moniliformis Lütken & Mortensen, 1899 32’ Arms without noded appearance........................................................................ 33 33 DAP bell-shaped with rounded edges............................... Ophiacantha costata Lütken & Mortensen, 1899 33’ DAP triangular with rounded edges..................................................................... 34 34 Dorsal disc with scattered and short multifid spines. RS semi-circular and not covered with multifid spines. Jaws bearing three oral papillae at each side, AdShSp lanceolate, LOPa one. Up to 7–8 serrated ArSp, approximately two arm segments in length. TSc almost as long as VAP............................................ Ophiacantha eurypoma H.L. Clark, 1911 34’ Dorsal disc totally covered with slender multifid spines. RS slender and covered with multifid spines. Jaws bearing 3–4 lanceolate oral papillae at each side, AdShSp flat, LOPa 1–2. Up to six smooth, blunt ArSp, almost one arm segment in length. Pointed TSc, shorter than the VAP................................ Ophiacantha pacifica Lütken & Mortensen, 1899 35 Dorsal disc with scales (largest in the center) and spines surrounding the margin of the disc and the RS. AdShSp shortest, not serrated, rounded. DAP not fragmented. Up to five pointed ArSp. One rounded TSc.... genus Dougaloplus, Dougaloplus sp. 35’ Dorsal disc with scales and scattered small spines mostly present around the margin of the disc. AdShSp largest, slightly serrated, rectangular. Some DAP fragmented in 2–3 pieces. Up to three blunt-tip ArSp. Two oval TSc.................................................................... genus Ophiocnida, Ophiocnida californica Ziesenhenne, 1940 36 Absence of oral papillae. Presence of 24–27 TPas. DAP not surrounded by symmetrical accessory plates.......................................................... genus Ophiothrix, Ophiothrix galapagensis Lütken & Mortensen, 1899 36’ Presence of oral papillae. Presence of numerous TPas. DAP surrounded by symmetrical accessory plates................................................................................................. genus Ophiopholis, 37 37 Dorsal disc (including RS) covered with scales and short multifid spines, those on the margin and the center elongated. Ventral interradii with elongated multifid spines. Up to 4–5 ArSp, first dorsalmost rudimentary................................................................................................... Ophiopholis bakeri McClendon, 1909 37’ Dorsal disc (usually absent from the RS) covered with scales and long spines, those on the margin more numerous. Ventral interradii with scales and some short spines. Up to 6–7, first dorsalmost the longest.................................................................................................... Ophiopholis longispina H.L. Clark, 1911, Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 11-13, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Doderlein, L. (1927) Indopacifische Euryalae. Abhandlungen der Mathematisch-Physikalischen Klasse der Koniglich Bayer Akademie der Wissenschaften, 31 (6), 1 - 105. https: // doi. org / 10.1515 / 9783486755459","Mu ¨ ller, J. H. & Troschel, F. H. (1842) System der Asteriden. F. Vieweg & Sohn, Braunschweig, 134 pp. https: // doi. org / 10.5962 / bhl. title. 11715","Lyman, T. (1875) II. Ophiuridae and Astrophytidae. Zoological results of the \" Hassler \" Expedition. Illustrated Catalogue of the Museum of Comparative Zoology at Harvard College, 8, 1 - 34.","Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Clark, A. H. (1921) A new ophiuran of the genus Ophiopsila from Southern California. Proceedings of the Biological Society of Washington, 34, 109 - 110.","Wyville-Thomson, C. (1873) The depths of the sea. An account of the general results of the dredging cruises of H. M. S. S. ' Porcupine' and ' Lightning' during the summers of 1868, 1869, and 1870, under the scientific direction of Dr. Carpenter, F. R. S, J. Gwyn Jeffreys, F. R. S., and Dr. Wyville Thomson, F. R. S. Macmillan and Co, London, 527 pp. https: // doi. org / 10.5962 / bhl. title. 19314","McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Lyman, T. (1860) Descriptions of New Ophiuridae, belonging to the Smithsonian Institution and to the Museum of Comparative Zoology at Cambridge. Proceedings of the Boston Society of Natural History, 7, 193 - 204 + 252 - 262. https: // doi. org / 10.5962 / bhl. part. 4822","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Lyman, T. (1879) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part II. Bulletin of the Museum of Comparative Zoology at Harvard College, 6 (2), 17 - 83.","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Lyman, T. (1883) Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Caribbean Sea (1878 - 79), and on the east coast of the United States, during the summer of 1880, by the U. S. coast survey steamer \" Blake \", commander J. R. Bartlett, U. S. N., commanding. XX. Report on the Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 10 (6), 227 - 287.","Ziesenhenne, F. C. (1940) New Ophiurans of the Allan Hancock Pacific Expeditions. Allan Hancock Pacific Expeditions, 8 (2), 9 - 52."]}

Ophiosphalma jolliense (McClendon, 1909) Fig. 3A‒F Ophiomusium jolliensis McClendon, 1909: 36, figs. 2‒3. Ophiomusium jolliense. H.L. Clark 1923: 154. Ophiosphalma jolliense. Hendler 1996: 164‒167, fig. 7.20a‒b.— Baker 2016: 33, fig. 53a‒b.— Lambert & Boutillier 2011: 48, fig. 34. Material examined. 31 individuals at seven stations. TALUD VIII, Sta. 11, 2 ind. (ICML-EMU-11058). TALUD XII, Sta. 23, 2 ind. (ICML-EMU-11057-A); Sta. 27, 3 ind. (ICML-EMU-11057-B) and 4 ind. (ICML-EMU-11057- C); Sta. 28, 4 ind. (ICML-EMU-11690). TALUD XV, Sta. 1, 2 ind. (ICML-EMU-11947-A); Sta. 23, 1 ind. (ICML-EMU-11947-B). TALUD XVIB, Sta. 28, 1 ind. (ICML-EMU-11059-A) and 12 ind. (ICML-EMU-11059-B). Comparative material. Possible type, 1 ind.: MCZ OPH-7048 (Supplementary file 2). The type material of Ophiosphalma jolliense was collected at three stations near San Diego and La Jolla, California, USA (McClendon 1909). This material is supposed to be deposited in the holdings of the University of California Museum (McClendon 1909); nevertheless, despite the exhaustive search for this material, it could not be located in this museum (pers. comm. Erica Clites & Carole Hickman 2018) or in any other institutions (i.e., LACM, MCZ, NHMD, USNM; pers. comm. Penny Benson 2016, Rich Mooi 2018). Baker (2016) designated lot MCZ OPH- 7048 as the holotype of O. jolliense, referring to the following: “This specimen was labeled ‒ O. clarkii McClendon ‒ there is no such species, and I assume McClendon decided on a different name for this species after writing a label. No locality data was on the label, but five examples of this species were collected at stations off Southern California at 115‒603 m, of which one must have been McClendon’s type”. During our study, we examined this lot, which contained the following original label: “Univ. Calif.- Dept. Zool. Ophiomusium clarkii, McClendon, 10”. According to the original description and figures, it certainly corresponds to O. jolliense. Baker´s arguments, however, are insufficient to determine whether or not this material corresponds to the original type series. According to the International Code of Zoological Nomenclature (ICZN 1999), Article 73.1, a holotype is a unique specimen on which a new nominal taxon of the species level is based in the original publication (i.e., McClendon 1909); therefore, specimen MCZ OPH- 7048 could not be designated as the holotype of O. jolliense by Baker (2016).At this moment, we consider that the status of the type material of O. jolliense cannot be resolved until the material used in the original description is located and corroborate whether specimen MCZ OPH- 7048 belongs to it. Description (ICML-EMU-11059-B). DD = 11 mm. Whole-body with tuberculous appearance. Disc pentagonal and flat. Dorsal disc covered with imbricated, irregular scales. Primary plates conspicuous, round, separated from each other. RS longer than broad, oval, separated by 3‒4 elongated scales, one quadrangular plate with rounded edges between each pair of RS, covering 1/3 of disc radius (Fig. 3A). Ventral interradii covered by oval, imbricated scales, slightly larger than dorsal scales. Genital slits with numerous minute quadrangular papillae (Fig. 3B). OSh longer than broad, elongated spearhead-shaped with distal lobe, rounded angles. Madreporite not evident. AdSh longer than broad, elongated, meeting in front of OSh. Jaws bearing 5‒6 papillae at each side, quadrangular, merged, two distalmost the largest; one pointed papilla at jaw tips (Fig. 3C). Arms thin, gradually narrowing distally. Dorsal arm base with 3‒4 imbricated DAP, with a granular appearance, projecting ventrally. DAP slightly broader than long, rhombic, proximally meeting, gradually separating and decreasing in size distally (Fig. 3D). First VAP smaller than rest; subsequent three VAP the largest (almost covering all arm segment length), separated from each other, the only ones with tentacle pores; posterior VAP triangular, reduced in size (approximately 1/3 arm segment in length), separated from each other. First LAP with two ArSp, separated; subsequent LAP with three ArSp, short (approximately 1/5 LAP in length). Three tentacle pores with one round TSc covering almost all the pore (Fig. 3E). Color pattern beige-whitish (Fig. 3A‒F). RS and primary plates darker than the rest of the body (ethanol preservation) (Fig. 3A). Habitat and distribution. From British Columbia, Canada to Colima, Mexico; one doubtful record off the Galapagos Islands; 155‒ 2,105 m depth (Hendler 1996; Lambert & Boutillier 2011; see Remarks), muddy substrates (H.L. Clark 1923). The material examined was collected off western Baja California and Baja California Sur, in the southern Gulf of California, and off Colima; 530‒ 1,532 m depth. Remarks. Hendler (2018) mentioned that Ophiosphalma jolliense has tooth papillae but did not provide information for the other oral papillae. For this reason, it was not possible to designate all oral papillae using the correct terminology in the present description and, for this matter, for any species included in Ophiosphalma. Ophiosphalma jolliense has been previously recorded off western Baja California Sur and in the southern Gulf of California (GranjaFernández et al. 2015). Present records off western Baja California and Colima extend its distribution in Mexico to the north (to 31º22′00″N; 117º01′60″W) and to the south (to 18º33′43″N; 103º57′45″W), respectively., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 17-18, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Clark, H. L. (1923) Echinoderms from Lower California with descriptions of new species: supplementary report. Bulletin of the American Museum of Natural History, 48 (6), 147 - 163.","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Baker, A. N. (2016) An illustrated catalogue of type specimens of the bathyal brittlestar genera Ophiomusium Lyman and Ophiosphalma H. L. Clark (Echinodermata: Ophiuroidea). Zootaxa, 4097 (1), 1 - 40. https: // doi. org / 10.11646 / zootaxa. 4097.1.1","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140.","ICZN [International Commission on Zoological Nomenclature] (1999) International Code of Zoological Nomenclature. Available from: https: // www. iczn. org / the-code / the-international-code-of-zoological-nomenclature / the-code-online / (accessed 15 June 2022)","Hendler, G. (2018) Armed to the teeth: a new paradigm for the buccal skeleton of brittle stars (Echinodermata: Ophiuroidea). Contribution in Science, 526, 189 - 311. https: // doi. org / 10.5962 / p. 324539"]}

Ophiosphalma variabile (Lütken & Mortensen, 1899) Fig. 3G‒L Ophiomusium variabile Lütken & Mortensen, 1899: 135‒137, pl. 4, figs. 4‒6. Ophiosphalma variabile. Hendler 1996: 166, fig. 7.20c‒d.— Baker 2016: 37, fig. 61a‒b. Material examined. 10,938 individuals at eight stations. TALUD III, Sta. 6, 166 ind. (ICML-EMU-9016-A), 2 ind. (ICML-EMU-9016-B), and 3 ind. (ICML-EMU-11067-A). TALUD IV, Sta. 3, 2 ind. (ICML-EMU-11116). TALUD V, Sta. 3, 8 ind. (ICML-EMU-11067-B). TALUD IX, Sta. 10, 1 ind. (ICML-EMU-11068-B); Sta. 17, 1 ind. (ICML-EMU-11068-A). TALUD XV, Sta. 5D, 161 ind. (ICML-EMU-11070); Sta. 20, 20 ind. (ICML-EMU-11071), 4 ind. (ICML-EMU-11685), and 1 ind. (ICML-EMU-11948); Sta. 23, 1 ind. (ICML-EMU-11069-A), 43 ind. (ICML-EMU-11069-B), 5,862 ind. (ICML-EMU-11220), and 4,663 ind. (ICML-EMU-11221). Comparative material. Ophiomusium variabile Lütken & Mortensen, 1899, syntypes, 6 ind.: MCZ OPH-507, USNM 19502 (Supplementary file 2). Description (ICML-EMU-11220). DD = 12 mm. Whole-body with weakly tuberculous appearance. Disc pentagonal, flat. Dorsal disc covered with imbricated, irregular size scales. Primary plates not evident. RS longer than broad, oval, separated by several elongated scales; several elongated oval scales between each pair of RS, covering ½ of disc radius (Fig. 3G). Ventral interradii covered by oval imbricated scales, larger than dorsal scales. Genital slits with numerous minute quadrangular papillae (Fig. 3H). OSh longer than broad, rhombic with a distal lobe, right angles. Madreporite slightly larger than OSh. AdSh longer than broad, elongated, quadrangular, almost meeting or meeting in front of OSh. Jaws bearing 6‒7 oral papillae at each side, quadrangular, merging, two distalmost the largest; one pointed papilla at jaw tips (Fig. 3I). Arms thin, gradually narrowing distally. Dorsal arm base with 3‒4 overlapping DAP, several granules at edges of arm base, projecting ventrally. DAP slightly longer than broad, rhombic, separating and decreasing in size distally (Fig. 3J). First VAP smaller than rest; subsequent three VAP the largest (almost covering all arm segment length), separated from each other, the only ones with tentacle pores; posterior VAP triangular, reduced in size (approximately 1/3 LAP in length), separated from each other. First LAP with two ArSp, separated; subsequent LAP with three ArSp. Three tentacle pores with one rounded TSc covering pore almost completely (Fig. 3K). Color pattern beige-whitish (ethanol preservation) (Fig. 3G‒L). Habitat and distribution. Mexican Pacific, from western Baja California Sur to Guerrero; 267‒ 1,148 m depth, muddy, sandy and rocky substrates (Lütken & Mortensen 1899; Maluf 1988; Granja-Fernández et al. 2015; see Remarks). The material examined was collected off western Baja California Sur, in the southern Gulf of California, and near Marias Islands; 530‒ 1,148 m depth. Remarks. Ophiosphalma variabile is similar to O. jolliense in overall appearance. However, differences in their morphology (e.g., radial shields size and lateral arm plates shape) are provided by Hendler (1996). Moreover, they can be distinguished by: 1) the primary plates are clearly visible in O. jolliense vs. not so in O. variabile, and 2) spearhead-shaped with rounded edges oral shields in O. jolliense vs. rhombic-shaped with right angle oral shields in O. variabile. The previous northernmost distribution limit of O. variabile was in the Gulf of California (GranjaFernández et al. 2015). Its presence off western Baja California Sur, as reported herein, represents a new distribution record in the Mexican Pacific as well as a general distribution range extension to the north (to 27ºN). The deepest known record (i.e., 902 m; Maluf 1988) is extended to 1,148 m., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 18-21, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Baker, A. N. (2016) An illustrated catalogue of type specimens of the bathyal brittlestar genera Ophiomusium Lyman and Ophiosphalma H. L. Clark (Echinodermata: Ophiuroidea). Zootaxa, 4097 (1), 1 - 40. https: // doi. org / 10.11646 / zootaxa. 4097.1.1","McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Asteronyx loveni Müller & Troschel, 1842 Fig. 1G‒M Asteronyx loveni Müller & Troschel, 1842: 119‒120, pl. 10, figs. 3‒5.—H.L. Clark 1913: 219.— Döderlein 1927: 59‒63, pl. 7, figs. 7‒8.— Kyte 1969a: 1737.— Lambert & Austin 2007: 71‒72, fig. 27.— Okanishi et al. 2011: 370‒371, fig. 2; 2017: 6‒12, figs. 1‒6. Asteronyx locardi Koehler, 1895: 88. Asteronyx dispar Lütken & Mortensen, 1899: 185, pl. 21, figs. 1‒2.—H.L. Clark 1913: 218. Asteronyx cooperi Bell, 1909: 22. Ophiuropsis lymani Studer, 1884: 85, pl. 5, figs. 12a‒d. Ophiuraster patersoni Litvinova, 1998: 441‒443, fig. 3. See Paterson (1985) for other synonymous records. Material examined.11 individuals at six stations. TALUD VI, Sta. 34, 1 ind. (ICML-EMU-11115). TALUD VIII, Sta. 11, 2 ind. (ICML-EMU-11110). TALUD IX, Sta. 21B, 1 ind. (ICML-EMU-9012). TALUD X, Sta. 22, 2 ind. (ICML-EMU-11112). TALUD XII, Sta. 29, 3 ind. (ICML-EMU-11111) and 1 ind. (ICML-EMU-11698). TALUD XIII, Sta. B, 1 ind. (ICML-EMU-11113). Comparative material. Asteronyx dispar Lütken & Mortensen, 1899, syntypes, 15 ind.: MCZ OPH-2816, MCZ OPH-2875, MCZ OPH-2876, USNM 19592, USNM 19593, USNM 19595, USNM 19596, USNM 19597 (Supplementary file 2). Description (ICML-EMU-11111). DD = 23 mm. Disc subpentagonal, indented interradially. Dorsal disc covered with thickened skin and sparse epidermal circular ossicles, lacking scales. RS clearly multilayered, elongated, thin, prominent distally, almost reaching the center of the disc (Fig. 1G). Ventral interradii entirely covered by integument with circular-shaped epidermal ossicles. Genital slits round, restricted to proximal part of the interradius, short, covering approximately 1/6 of interradius. OSh not evident (Fig. 1H). One small circular madreporite.AdSh broader than long, rectangular with rounded edges, meeting in front of OSh. Jaws bearing seven papillae at each side; OPa four, granule-like; TPa three at jaw tips, spiniform, larger than OPa, separated. Teeth several, similar to TPa (Fig. 1I). Arms entirely covered by integument, coiled, gradually narrowing distally (Fig. 1J); two arms wider and slightly shorter than the remaining three. LAP located on the ventral lateral side of vertebrae, rounded, prominent (Fig. 1K). First tentacle pore lacking ArSp; second with one ArSp; subsequent pores gradually reaching up to 6‒7 ArSp in the middle of the arm, hook-shaped, serrated (Fig. 1K). Middle part of the arm with ventralmost ArSp very elongated (approximately two VAP in length), bulbous (Fig. 1L). TSc lacking. Color pattern yellowish-brown (ethanol preservation) (Fig. 1G‒M). Habitat and distribution. Widely distributed in deep waters worldwide, except polar regions (Paterson 1985). In the eastern tropical Pacific, A. loveni has been reported from Mexico, Panama, and the Galapagos Islands (Lütken & Mortensen 1899; Maluf 1991; Granja-Fernández et al. 2015); 100‒ 4,721 m, but more common at 200‒ 2,000 m depth (Paterson 1985; Okanishi et al. 2018). Associated with gorgonians and Pennatulacea (Fujita & Ohta 1988). The material of the TALUD cruises is from the southern Gulf of California and off Jalisco; 920‒ 1,643 m depth, associated with unidentified gorgonians. Remarks. Asteronyx loveni has been recorded in Mexico in the Gulf of California and off western Baja California and Baja California Sur (Granja-Fernández et al. 2015). During the TALUD cruises it was collected further south, off Jalisco (19º19′37″N; 105º26′20″W), which represents a significant extension of its distribution in western Mexico. Some of the TALUD specimens were associated with unidentified gorgonians. The arms of A. loveni have a specific function since the two wider arms firmly attach to the substrate (the gorgonians in this case), and the remainder, long and slender arms, extend into the water column to collect particles used for feeding (Paterson 1985; Fujita & Ohta 1988). Genetic data show considerable diversity suggesting that A. loveni might be a complex of several closely related species (Christodoulou et al. 2019)., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 14, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Mu ¨ ller, J. H. & Troschel, F. H. (1842) System der Asteriden. F. Vieweg & Sohn, Braunschweig, 134 pp. https: // doi. org / 10.5962 / bhl. title. 11715","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Doderlein, L. (1927) Indopacifische Euryalae. Abhandlungen der Mathematisch-Physikalischen Klasse der Koniglich Bayer Akademie der Wissenschaften, 31 (6), 1 - 105. https: // doi. org / 10.1515 / 9783486755459","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Lambert, P. & Austin, W. (2007) Brittle stars, sea urchins and feather stars of British Columbia, Southeast Alaska and Puget Sound. Royal BC Museum Handbook, Victoria, 150 pp.","Okanishi, M., Yamaguchi, K., Horii, Y., & Fujita, T. (2011) Ophiuroids of the order Euryalida (Echinodermata) from Hachijo ¯ jima Island and Ogasawara Islands, Japan. Memoirs of the Natural History Museum of Sciences Tokyo, 47, 367 - 385.","Koehler, R. (1895) Dragages profonds executes a bord du Caudan dans le Golfe de Gascogne. Rapport preliminaire sur les Echinodermes. Revue biologique du Nord de la France, 7, 439 - 496.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Bell, F. J. (1909) Report on the echinoderma (other than holothurians) collected by Mr. J. Stanley Gardiner in the western parts of the Indian Ocean. Transactions of the Linnean Society of London, 2 nd Series, Zoology, 13, 17 - 22. https: // doi. org / 10.1111 / j. 1096 - 3642.1909. tb 00406. x","Studer, T. (1884) Verzeichnis der wahrend der Reise S. M. S. \" Gazelle \" um die Erde, 1874 - 76 gesammelten Asteriden und Euryaliden. Abhandlungen der Preussischen Akademie der Wissenschaften, 2, 1 - 64.","Litvinova, N. M. (1998) Two new species of the genus Ophiuraster (Ophiurinae, Ophiuroidea, Echinodermata) from French collections and some remarks on the genus. Zoosystema, 20 (3), 439 - 444.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Maluf, L. Y. (1991) Echinoderm fauna of the Galapagos Islands. In: James, M. J. (Ed.), Galapagos marine invertebrates: taxonomy, biogeography, and evolution in Darwin's Islands. Plenum, New York, New York, pp. 345 - 367. https: // doi. org / 10.1007 / 978 - 1 - 4899 - 0646 - 5 _ 17","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Okanishi, M., Sentoku, A., Martynov, A. & Fujita, T. (2018) A new cryptic species of Asteronyx Mu ¨ ller & Troschel, 1842 (Echinodermata: Ophiuroidea), based on molecular phylogeny and morphology, from off Pacific Coast of Japan. Zoologischer Anzeiger, 274 (2018), 14 - 33. https: // doi. org / 10.1016 / j. jcz. 2018.03.001","Fujita, T. & Ohta, S. (1988) Photographic observations of the life style of a deep-sea ophiuroid Asteronyx loveni (Echinodermata). Deep-Sea Research, 35 (12), 2029 - 2043. https: // doi. org / 10.1016 / 0198 - 0149 (88) 90123 - 9","Christodoulou, M., O'Hara, T. D., Hugall, A. F. & Martinez-Arbizu, P. (2019) Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology Report, 29, 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012"]}

Ophiolimna bairdi (Lyman, 1883) Fig. 11A‒F Ophiacantha bairdi Lyman, 1883: 256, pl. 5, figs. 70‒72. Ophiolimna bairdi. Lütken & Mortensen 1899: 177, pl. 18, figs. 9‒13.— H.L. Clark 1911: 230‒231.— Kyte 1969a: 1738.— Paterson 1985: 60, fig. 24.— Martynov 2010: 68, figs. 13g, 28c, 44a, 81a‒b, 82a, 82d, 82g, 82j.— Martynov & Litvinova 2008: 100‒101, fig. 17a.— Lambert & Boutillier 2011: 44, fig. 30.— O’Hara & Thuy 2022: 28, fig. 6g ‒h. See Paterson (1985) and O’Hara & Thuy (2022) for other synonymous records. Material examined. 95 individuals at seven stations. TALUD VIII, Sta. 3, 11 ind. (ICML-EMU-11209); Sta. 11, 5 ind. (ICML-EMU-11210-B); Sta. 15, 10 ind. (ICML-EMU-11210-A); Sta. 22, 26 ind. (ICML-EMU-11211). TALUD XII, Sta. 26, 1 ind. (ICML-EMU-11212-B); Sta. 27, 16 ind. (ICML-EMU-11212-A). TALUD XIII, Sta. 37, 26 ind. (ICML-EMU-11213). Comparative material. Ophiacantha bairdi Lyman, 1883, holotype: MCZ OPH-1916. Paratypes, 2 ind.: MCZ OPH-1917, MNHN-IE-2013-10324 (Supplementary file 2). Description (ICML-EMU-11211). DD = 10.8 mm. Disc pentagonal, flat. Dorsal disc covered by elongated granules and few scattered elongated spines. Primary plates and RS covered by granules (Fig. 11A). Ventral interradii covered by granules similar to dorsal granules (Fig. 11B). OSh broader than long, triangular with rounded edges. Madreporite with a rounded depression. AdSh longer than broad, slender, triangular, separated from each other. Oral plate conspicuous, covered by granules projected to OSh and AdSh. Jaws bearing five papillae at each side; AdShSp rounded; LOPa three, first LOPa oval, the rest elongated, pointed; IPa very pointed, large. vT similar in appearance to IPa but shorter (Fig. 11C). Arms fragile. First DAP covered by granules; subsequent DAP slightly longer than broad, triangular with rounded edges, slightly separated from each other (Fig. 11D). VAP slightly longer than broad, pentagonal, meeting. VAP and LAP with conspicuous horizontal striations, respectively. LAP with 7‒8 ArSp, large (approximately three arm segments in length), smooth, pointed. Tentacle pores with one lanceolate TSc (Fig. 11E). Color pattern in dorsal and ventral disc and arms brown (ethanol preservation) (Fig. 11A‒F). Habitat and distribution. Widely distributed in the Atlantic and Pacific Oceans (Lambert & Boutillier 2011). In the Pacific it has been reported from Japan, the Okhotsk Sea, Alaska, USA, Mexico, Costa Rica, and Panama (Lütken & Mortensen 1899; H.L. Clark 1911; Lambert & Boutillier 2011; Granja-Fernández et al. 2015); 620‒ 2,600 m depth (Martynov 2010), muddy substrates (Lütken & Mortensen 1899). The material examined was collected in the southern Gulf of California and off Colima; 920‒ 2,200 m depth. Remarks. In the material examined, even smaller specimens (DD = 5 mm) presented the characteristic horizontal striations in the ventral and lateral arm plates but with a tuberculous appearance. Moreover, these small specimens had denser spines on the dorsal disc than larger specimens. Due to its wide geographic distribution, a thorough morphological and molecular approach is needed to elucidate whether it may be a cryptic species complex. In Mexico, Ophiolimna bairdi had previously been documented off western Baja California Sur and in the Gulf of California (Granja-Fernández et al. 2015); its presence off Colima represents a new distribution record for Mexico., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 40, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1883) Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Caribbean Sea (1878 - 79), and on the east coast of the United States, during the summer of 1880, by the U. S. coast survey steamer \" Blake \", commander J. R. Bartlett, U. S. N., commanding. XX. Report on the Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 10 (6), 227 - 287.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Martynov, A. (2010) Reassessment of the classification of the Ophiuroidea (Echinodermata), based on morphological characters. I. General character evaluation and delineation of the families Ophiomyxidae and Ophiacanthidae. Zootaxa, 2697 (1), 1 - 154. https: // doi. org / 10.11646 / zootaxa. 2697.1.1","Martynov, A. V. & Litvinova, N. M. (2008) Deep-water Ophiuroidea of the northern Atlantic with descriptions of three new species and taxonomic remarks on certain genera and species. Marine Biology Research, 4 (1 - 2), 76 - 111. https: // doi. org / 10.1080 / 17451000701840066","Lambert, P. & Boutillier, J. (2011) Deep-sea Echinodermata of British Columbia, Canada. Canadian Technical Report of Fisheries and Aquatic Sciences, 2929, 1 - 140.","O'Hara, T. D. & Thuy, B. (2022) Biogeography and taxonomy of Ophiuroidea (Echinodermata) from the I ˆ les Saint-Paul and Amsterdam in the southern Indian Ocean. Zootaxa, 5124 (1), 1 - 49. https: // doi. org / 10.11646 / zootaxa. 5124.1.1","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Amphiophiura oligopora (H.L. Clark, 1913) Fig. 5G‒L Ophiura oligopora H.L. Clark, 1913: 210‒211, pl. 35, figs. 8‒9. Material examined. 74 individuals in seven stations. TALUD VIII, Sta. 3, 1 ind. (ICML-EMU-11128-B). TALUD XII, Sta. 23, 2 ind. (ICML-EMU-11129-A); Sta. 28, 67 ind. (ICML-EMU-11139). TALUD XV, Sta. 5C, 1 ind. (ICML-EMU-11131-A); Sta. 24, 1 ind. (ICML-EMU-11131-C). TALUD XVIB, Sta. 23, 1 ind. (ICML-EMU-11132-A); Sta. 28, 1 ind. (ICML-EMU-11132-B). Comparative material. Ophiura oligopora H.L. Clark, 1913, holotype: USNM 31641. Paratype, 1 ind.: MCZ OPH-3618 (Supplementary file 2). Description (ICML-EMU-11139). DD = 9.4 mm. Disc pentagonal with a central depression. Dorsal disc covered by irregular oval scales. Primary plates oval, conspicuous, separated from each other. RS longer than broad, triangular, separated by large scales, only meeting distally; one oval plate at disc margin between each pair of RS (Fig. 5G). Ventral interradii covered by few scales, similar size to dorsal scales. Genital slits with minute, pointed genital papillae, projecting dorsally and forming discrete arm combs with small, rounded papillae (Fig. 5H). OSh longer than broad, pentagonal proximally, quadrangular with rounded edges distally. Madreporite not evident. AdSh longer than broad, elongated, slender, meeting in front of OSh. Jaws bearing five papillae at each side; BSc rectangular, very elongated; IPa similar to BSc but smaller; 2IPa quadrangular, elongated; TPa two pointed, apicalmost the largest. vT pointed, more large than oral papillae. Preceding ossicles separated by a diastema; one AdShSp, two 2AdShSp, rounded (Fig. 5I). Arms gradually narrowing distally. First three DAP broader than long, overlapping; subsequent DAP longer than broad, trapezoidal, meeting (Fig. 5J). VAP broader than long, oval, separating and decreasing in size distally (Fig. 5K). LAP with three ArSp, short (approximately 1/5 LAP in length), pointed, dorsalmost the longest, often widened at the tip (Fig. 5J). First tentacle pore with three rounded TSc; subsequent tentacle pores with one and none TSc distally (Fig. 5K). Color pattern beige-whitish (Fig. 5G‒L). RS and large plate between them and arms with dark brown tint (ethanol preservation) (Fig. 5G, J). Habitat and distribution. Only known in western Mexico; 772‒ 1,532 m depth, sandy and muddy substrates (H.L. Clark 1913; Granja-Fernández et al. 2015; see Remarks). The material examined was collected off western Baja California and Baja California Sur, in the southern Gulf of California, and off Colima; 772‒ 1,532 m depth. Remarks. Amphiophiura oligopora requires revision since the genus Amphiophiura is characterized by having massive oral shields (Matsumoto 1917), a character absent in A. oligopora. It is therefore reported herein as a doubtful member of this genus. The only previously known material of A. oligopora corresponds to the type material (holotype and one paratype) collected in the southern Gulf of California at 1,152 m depth (H.L. Clark 1913). The finding of new material of this species at six localities during the TALUD cruises is therefore very relevant since it represents the only non-type material available to date. It represents new distribution range limits to the north (31º22′00″N; 117º01′60″W) and to the south (18º33′43″N; 103º57′45″W) as well as a new bathymetric distribution range (772‒ 1,532 m)., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 25-27, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Lyman, T. (1878) Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology at Harvard College, 5 (7), 65 - 168.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Matsumoto, H. (1917) A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo, 32 (2), 1 - 408."]}

Ophiomusa lymani (Wyville-Thomson, 1873) Fig. 4A‒F Ophiomusium lymani Wyville-Thomson, 1873: 174‒175, figs. 32‒33.—Lütken & Mortensen 1899: 137‒139, pl. 3, figs. 8‒ 11.— H.L. Clark 1913: 213‒214; 1917: 450; 1923: 154.— Kyte 1969a: 1738.— Tyler 1980: 129, fig. 2a‒b.— Martynov & Litvinova 2008: 87, 90, fig. 6h. Ophiomusa lymani. O’Hara et al. 2018: 8.— O’Hara & Thuy 2022: 13‒14, fig. 5a‒g. See Paterson (1985) and O’Hara & Thuy (2022) for other synonymous records. Material examined. 1,108 individuals at 15 stations. TALUD IV, Sta. 14, 2 ind. (ICML-EMU-11073). TALUD XII, Sta. 5, 23 ind. (ICML-EMU-11074); Sta. 8, 1 ind. (ICML-EMU-11075-B); Sta. 9, 1 ind. (ICML-EMU-11075-A); Sta. 24, 3 ind. (ICML-EMU-11076); Sta. 25, 178 ind. (ICML-EMU-11077); Sta. 29, 249 ind. (ICML-EMU-11078), 259 ind. (ICML-EMU-11079), and 2 ind. (ICML-EMU-11684). TALUD XVIB, Sta. 1, 2 ind. (ICML-EMU-11080- A) and 1 ind. (ICML-EMU-11080-B); Sta. 9, 2 ind. (ICML-EMU-11081), 6 ind. (ICML-EMU-11082), and 35 ind. (ICML-EMU-11083); Sta. 15, 40 ind. (ICML-EMU-11084) and 59 ind. (ICML-EMU-11085); Sta. 20, 15 ind. (ICML-EMU-11086); Sta. 21, 2 ind. (ICML-EMU-11087); Sta. 22, 5 ind. (ICML-EMU-11088); Sta. 27, 194 ind. (ICML-EMU-11089-A), 1 ind. (ICML-EMU-11089-B), and 18 ind. (ICML-EMU-11090); Sta. 28, 10 ind. (ICML-EMU-11091). Comparative material. Type material not examined. While examining material deposited at the British Museum of Natural History, Baker (2016) designated a lectotype (BMNH 90.2.19.9.10) and a paralectotype (no catalog number available) of O. lymani. Unfortunately, it was impossible to examine these specimens during the present work. Description (ICML-EMU-11078). DD = 23 mm. Disc round, flat. Dorsal disc with strongly tuberculous appearance, mainly on RS and large marginal interradial plates; covered with imbricated, irregular scales. Primary plates not evident, except for a central polygonal primary plate. RS longer than broad, triangular, very conspicuous, separated by a single row of scales; one pentagonal plate at disc margin between each pair of RS with tuberculous appearance (Fig. 4A). Ventral interradii covered by few irregular scales, much larger than dorsal scales (Fig. 4B). OSh longer than broad, pentagonal proximally, quadrangular distally. Madreporite not evident. AdSh longer than broad, elongated, rectangular, meeting in front of OSh. Jaws bearing 5‒7 papillae at each side; AdShSp rectangular, elongated, the largest; 2AdShSp rectangular, smaller than AdShSp; BSc similar in shape, larger than 2AdShSp; IPa quadrangular; 2IPa at jaw tips, similar to IPa. vT rounded (Fig. 4C). Arms slender. First two DAP much reduced, overlapping; subsequent DAP slightly broader than long, rhombic, small (approximately 1/3 LAP in length), separating, decreasing in size distally (Fig. 4D). First VAP smaller than rest; subsequent two VAP pentagonal, almost meeting, the only ones with tentacle pores. Posterior VAP lacking. LAP with up to seven ArSp, very short (approximately 1/5 LAP in length), pointed. Two tentacle pores with one oblong TSc fully covering all the pore (Fig. 4E). Color pattern beige-whitish (ethanol preservation) (Fig. 4A‒F). Habitat and distribution. Widely distributed in the Pacific, Indian, and Atlantic Oceans (Paterson 1985). In the eastern Pacific from British Columbia, Canada, to Chile; 630‒ 2,906 m depth, muddy and sandy substrates (Lütken & Mortensen 1899; Maluf 1988). The material examined was collected off western Baja California, in the entrance of the Gulf of California, and off Jalisco, Colima, and Guerrero; 1,392 ‒2,250 m depth. Remarks. The material examined here presented up to seven arm spines; however, Paterson (1985) indicated that this species could display up to 12 arm spines. Ophiomusa lymani can easily be distinguished from the rest of the deep-water ophiuroids from the eastern Pacific by their tuberculous disc, the large radial shields (covering approximately ½ disc radius) with tuberculous surface, the presence of two tentacle pores, and the absence of ventral arm plates in almost the entire arm. Widely distributed in the eastern Pacific, but in Mexico only recorded in the Gulf of California, off western Baja California and Baja California Sur, and off Marias Islands (Granja-Fernández et al. 2015). Material from off Jalisco, Colima, and Guerrero represent new distribution records for these areas, including (Guerrero) the southernmost record in western Mexico., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 21-22, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Wyville-Thomson, C. (1873) The depths of the sea. An account of the general results of the dredging cruises of H. M. S. S. ' Porcupine' and ' Lightning' during the summers of 1868, 1869, and 1870, under the scientific direction of Dr. Carpenter, F. R. S, J. Gwyn Jeffreys, F. R. S., and Dr. Wyville Thomson, F. R. S. Macmillan and Co, London, 527 pp. https: // doi. org / 10.5962 / bhl. title. 19314","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1913) Echinoderms from Lower California, with descriptions of new species. Bulletin of the American Museum of Natural History, 32, 185 - 236. https: // doi. org / 10.5962 / bhl. title. 1734","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Clark, H. L. (1923) Echinoderms from Lower California with descriptions of new species: supplementary report. Bulletin of the American Museum of Natural History, 48 (6), 147 - 163.","Kyte, M. A. (1969 a) A synopsis and key to the recent Ophiuroidea of Washington State and Southern British Columbia. Journal of the Fisheries Research Board of Canada, 26 (7), 1727 - 1741. https: // doi. org / 10.1139 / f 69 - 160","Tyler, P. A. (1980) Deep-sea ophiuroids. Oceanography and Marine Biology Annual Review, 18, 125 - 153.","Martynov, A. V. & Litvinova, N. M. (2008) Deep-water Ophiuroidea of the northern Atlantic with descriptions of three new species and taxonomic remarks on certain genera and species. Marine Biology Research, 4 (1 - 2), 76 - 111. https: // doi. org / 10.1080 / 17451000701840066","O'Hara, T. D., Stohr, S., Hugall, A. F., Thuy, B. & Martynov, A. (2018) Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification. European Journal of Taxonomy, 416, 1 - 35. https: // doi. org / 10.5852 / ejt. 2018.416","O'Hara, T. D. & Thuy, B. (2022) Biogeography and taxonomy of Ophiuroidea (Echinodermata) from the I ˆ les Saint-Paul and Amsterdam in the southern Indian Ocean. Zootaxa, 5124 (1), 1 - 49. https: // doi. org / 10.11646 / zootaxa. 5124.1.1","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Baker, A. N. (2016) An illustrated catalogue of type specimens of the bathyal brittlestar genera Ophiomusium Lyman and Ophiosphalma H. L. Clark (Echinodermata: Ophiuroidea). Zootaxa, 4097 (1), 1 - 40. https: // doi. org / 10.11646 / zootaxa. 4097.1.1","Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Histampica cf. duplicata (Lyman, 1875) Fig. 18A‒F Material examined. 31 individuals at five stations. TALUD XII, Sta. 8, 6 ind. (ICML-EMU-11705); Sta. 25, 1 ind. (ICML-EMU-11671); Sta. 27, 1 ind. (ICML-EMU-11715). TALUD XIV, Sta. 10, 8 ind. (ICML-EMU-12996). TALUD XV, Sta. 1, 15 ind. (ICML-EMU-11672). Comparative material. Amphiura duplicata Lyman, 1875 (original name of Histampica duplicata (Lyman, 1875)), syntypes, 3 ind.: MCZ OPH- 1262, MCZ OPH- 1264, MCZ OPH- 4092 (Supplementary file 2). Description (ICML-EMU-12996). DD = 5.4 mm. Disc slightly incised interradially. Dorsal disc covered by imbricated, depressed scales, no disc spines. Central primary plate round, surrounded by oval primary plates. RS scalene triangular, separated by three large scales (Fig. 18A). Ventral interradii covered by imbricated scales smaller than dorsal scales (Fig. 18B). OSh broader than long, spearhead-shaped with pronounced distal lobe. Madreporite slightly larger than OSh. AdSh trapezoidal, meeting in front of OSh. Jaws bearing four oral papillae at each side; AdShSp rounded; 2AdShSp quadrangular; BSc pointed; IPa pointed. vT quadrangular-rounded (Fig. 18C). Arms slender. DAP broader than long, triangular, twice as wide as long, distal edge convex, separated (Fig. 18D). VAP broader than long, pentagonal, separated. LAP with up to three ArSp, small (approximately one arm segment in length), blunt tip, dorsalmost the longest, ventralmost the shortest. Tentacle pores with two oval TSc (Fig. 18E). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 18A‒F). Habitat and distribution. The material examined is from western Baja California Sur, the Gulf of California, and off Colima and Guerrero; 325‒ 1,940 m depth, mostly on muddy bottom. Remarks. Histampica duplicata is known from the Gulf of Vizcaya to South Africa, the North Atlantic, the Gulf of Mexico, the Caribbean, Barbados, and Brazil, and also in the eastern Pacific (Lyman 1875; Lütken & Mortensen 1899; H.L. Clark 1917; Paterson 1985; Granja-Fernández et al. 2015; Stöhr et al. 2022). The first record in the eastern Pacific was by Lütken & Mortensen (1899), who observed morphological differences between their specimens from Malpelo and Galapagos Islands and the type material from Barbados. We also observed differences in the Mexican Pacific morphology comparatively with the type material, including 1) very well-formed and conspicuous rosette of primary plates in H. duplicata, 2) smaller radial shields in H. duplicata, and 3) spearheadshaped oral shields without a distal lobe in H. duplicata. The above differences may be due to the specimens’ size or to a variation due to regional environmental conditions. The Mexican-eastern Pacific morphology may represent another species, but detailed morphological and molecular analyses are needed to confirm this., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 57-58, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Lyman, T. (1875) II. Ophiuridae and Astrophytidae. Zoological results of the \" Hassler \" Expedition. Illustrated Catalogue of the Museum of Comparative Zoology at Harvard College, 8, 1 - 34.","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer \" Albatross \" from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.","Paterson, G. L. J. (1985) The deep-sea Ophiuroidea of the North Atlantic Ocean. Bulletin of the British Museum (Natural History) Zoology, 49 (1), 1 - 162.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.","Stohr, S., O'Hara, T. & Thuy, B. (2022) World Ophiuroidea database. Available from: http: // marinespecies. org / aphia. php? p = search (accessed 15 April 2022)"]}

Genus Dougaloplus A.M. Clark, 1970 Species of Dougaloplus reported in the eastern Pacific were originally described in the genera Amphiura and Ophiocnida (Lütken & Mortensen 1899; McClendon 1909) and subsequently transferred to Amphiacantha, a preoccupied genus, by Matsumoto (1917). Consequently, A.M. Clark (1970) proposed the replacement name Dougaloplus for the genus. Some authors have described a few characteristics of Dougaloplus (e.g., disc covered with scales and spines, 1‒2 tentacle scales, 3‒6 arm spines; Matsumoto 1917; A.M. Clark 1970); however, a proper diagnosis of the genus is lacking so far., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on page 55, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, A. M. (1970) Notes on the family Amphiuridae (Ophiuroidea). Bulletin of the British Museum (Natural History) Zoology, 19, 1 - 81. https: // doi. org / 10.5962 / bhl. part. 24085","Lu ¨ tken, C. F. &. Mortensen, T. (1899) The Ophiuridae. Memoirs of the Museum of Comparative Zoology at Harvard College, 23 (2), 93 - 208.","McClendon, J. F. (1909) The ophiurans of the San Diego region. University of California Publications in Zoology, 6 (3), 33 - 64.","Matsumoto, H. (1917) A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo, 32 (2), 1 - 408."]}

Amphiura arcystata H.L. Clark, 1911 Fig. 14A‒F Amphiura acrystata H.L. Clark, 1911: 145‒148, fig. 58 (lapsus calamus for arcystata) Amphiura arcystata. H.L. Clark 1915: 224; 1940: 336; 1970: 10‒11.— Nielsen 1932: 264.— Ziesenhenne 1937: 223.— Boolotian & Leighton 1966: 4, 8, fig. 7.— Hendler 1996: 145‒147. Hemilepis arcystata. Fell 1962: 10, 19. See Hendler (1996) for other synonymous records. Material examined. One individual at one station. TALUD XV, Sta. 23, 1 ind. (ICML-EMU-12995). Comparative material. Holotype: USNM 25623. Paratypes, 53 ind.: MCZ OPH-3135, MCZ OPH-3136, MCZ OPH-3137, MCZ OPH-3138, MCZ OPH-3368, MCZ OPH-3369, USNM 25834, USNM 25837, USNM 26078, USNM 26130, USNM 26188, USNM 26197, USNM 26609, USNM 27094, USNM 27124, USNM 33638 (Supplementary file 2). Description (ICML-EMU-12995). DD = 5.3 mm. Disc strongly shrinked due to preservation. Dorsal disc covered mostly by integument, imbricated scales around RS. Primary plates not evident. RS very conspicuous, thicker distally, in contact only distally, the rest separated by scales (Fig. 14A). Ventral interradii covered by scaleless integument (Fig. 14B). OSh broader than long, oval, with distal lobe. Madreporite larger than OSh. AdSh triangular, separated interradially and radially. Jaws bearing three oral papillae at each side; AdShSp elongated when present; BSc elongated, pointed; IPa rounded. vT quadrangular (Fig. 14C). Arms slender, elongated. DAP broader than long, oval, meeting (Fig. 14D). VAP a little broader than long, almost quadrangular, meeting. LAP with five ArSp, small (approximately one arm segment in length), pointed, ventralmost the longest and dorsalmost the shortest. Tentacle pores with two oval TSc (Fig. 14E). Color pattern in dorsal and ventral disc and arms beigewhitish (ethanol preservation) (Fig. 14A‒F). Habitat and distribution. Japan, California, USA, Mexico, Costa Rica, Colombia, and the Galapagos Islands (H.L. Clark 1911; Maluf & Brusca 2005); 60‒848 m depth, muddy and sandy substrates (H.L. Clark 1911; Ziesenhenne 1937; Hendler 1996). The material examined was collected off western Baja California Sur; 625 m depth. Remarks. During the TALUD cruises, only one specimen of Amphiura arcystata was collected and it is smaller than the holotype (USNM 25623, DD = 10 mm). The specimen differs in the number of arm spines (5 vs. 6‒7 in the holotype) and the thickness of the radial shields (thicker in the smaller specimen). Juvenile or small individuals of A. arcystata are known to significantly differ morphologically from adults, and it has been recorded that this species shows a great morphological variability regardless of size (H.L. Clark 1911; Hendler 1996). In this respect, the revision of the type material evidenced two morphologies (one from Japan ‒USNM 26130, MCZ OPH-3137 and the other from California‒USNM 25623, MCZ OPH-3135, MCZ OPH-3369) featuring differences in the presenceabsence of scales and integument in dorsal disc, the shape of the radial shields, oral shields, dorsal arm plates, ventral arm plates, and arm spines. The unique specimen collected during this survey agrees with the holotype from California. Japan and California morphologies probably correspond to different species, but more morphological and molecular evidence is needed. Due to the significant morphological variability observed here, we recommend reviewing the material of A. arcystata from Central and South America (Costa Rica, Colombia, and the Galapagos Islands). In Mexico, it has previously been collected off western Baja California, in the Gulf of California, and off Guerrero (Granja-Fernández et al. 2015). The current record is a first for the west coast of Baja California Sur., Published as part of Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, pp. 1-71 in Zootaxa 5259 (1) on pages 47-48, DOI: 10.11646/zootaxa.5259.1.1, http://zenodo.org/record/7794984, {"references":["Clark, H. L. (1911) North Pacific Ophiurans in the collection of the United States National Museum. U. S. National Museum Bulletin, 75, 1 - 302. https: // doi. org / 10.5479 / si. 03629236.75.1","Clark, H. L. (1915) Catalogue of recent ophiurans. Memoirs of the Museum of Comparative Zoology, 25 (4), 163 - 376.","Clark, H. L. (1940) Eastern Pacific Expeditions of the New York Zoological Society. XXI. Notes on Echinoderms from the West Coast of Central America. Zoologica, 25 (22), 331 - 352. https: // doi. org / 10.5962 / p. 184708","Clark, A. M. (1970) Notes on the family Amphiuridae (Ophiuroidea). Bulletin of the British Museum (Natural History) Zoology, 19, 1 - 81. https: // doi. org / 10.5962 / bhl. part. 24085","Nielsen, E. (1932) Ophiurans from the Gulf of Panama, California and the Strait of Georgia. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening, 91, 241 - 346.","Ziesenhenne, F. C. (1937) The Templeton Crocker Expedition. X. Echinoderms from the West Coast of Lower California, the Gulf of California and Clarion Island. Zoologica, 22 (15), 209 - 239. https: // doi. org / 10.5962 / p. 184686","Boolotian, R. A. & Leighton, D. (1966) A key to the species of Ophiuroidea (brittle stars) of the Santa Monica Bay and adjacent areas. Los Angeles County Museum Contributions in Science, 93, 1 - 20. https: // doi. org / 10.5962 / p. 241083","Hendler, G. (1996) Taxonomic atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Class Ophiuroidea. Santa Barbara Museum of Natural History, 14, 113 - 179.","Fell, B. H. (1962) A revision of the major genera of Amphiuroid Ophiuroidea. Transactions of the Royal Society of New Zealand, Zoology, 2 (2), 1 - 26.","Maluf, L. Y. & Brusca, R. C. (2005) Chapter 18. Echinodermata. In: Hendrickx, M. E., Brusca, R. C. & Findley, L. T. (Eds.), A Distributional checklist of the macrofauna of the Gulf of California, Mexico. Arizona-Sonora Desert Museum, Tucson, Arizona, pp. 327 - 343.","Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47."]}

Deep-sea ophiuroids were collected by the manned submersible ‘Shenhaiyongshi’ from the South China Sea at depths of 500–3550 m, in 2017 to 2020. A total of 18 species were identified, including three new species and eight new records, increasing the total number of species known from the South China Sea to 304. Most of the ophiuroids recorded from the South China Sea were found in shallow waters (77.9%) and a few of them occurred only in deep water (20.4%). Three new species are described as Ophiacantha aster sp. nov., Ophiomoeris petalis sp. nov. and Ophiopristis shenhaiyongshii sp. nov. We provide comprehensive descriptions of morphological features, including characteristics of the arm skeletons, and a phylogenetic analysis based on COI and 16S sequences. Overall intraspecific and interspecific genetic distance variations among the families found in this study were 0.5% to 2.47% and 1.16% to 44.16%, respectively, along the South Pacific region to the South China Sea. Our phylogenetic analysis suggested that COI partial genes resolved the interspecies complexity in the class Ophiuroidea better than 16S partial genes. The order Euryalida had low interspecies genetic distance variation within the class Ophiuroidea. The present study suggests a high probability that species of Asteroschema and Gorgonocephalus are more widely spread around the Indo-Pacific region than previously expected.

The Lower Triassic fossil record of brittle stars is relatively rich, yet most records published to date are based on poorly preserved or insufficiently known fossils. This hampers exhaustive morphological analyses, comparison with recent relatives or inclusion of Early Triassic ophiuroid taxa in phylogenetic estimates. Here, we describe a new ophiuroid from the Lower Triassic of Nevada, preserved as phosphatized skeletal parts and assigned to the new taxon Ophiosuperstes praeparvus gen. et sp. nov Maxwell, V. & Pruss. S.B. This unusual preservation of the fossils allowed for acid-extraction of an entire suite of dissociated skeletal parts, including lateral arm plates, ventral arm plates, vertebrae and various disk plates, thus unlocking sufficient morphological information to explore the phylogenetic position of the new taxon. Bayesian phylogenetic inference suggests a basalmost position of O. praeparvus within the Ophintegrida, sister to all other sampled members of that superorder. The existence of coeval but more derived ophiuroids suggests that O. praeparvus probably represents a member of a more ancient stem ophintegrid group persisting into the Early Triassic.

Humara-Gil, Karla J., Granja-Fernández, Rebeca, Bautista-Guerrero, Eric, Rodríguez-Troncoso, Alma P. (2022): Overlooked for over a century: Ophioderma occultum sp. nov. (Echinodermata), a new species of brittle star from the Eastern Pacific. Journal of Natural History (J. Nat. Hist.) 56 (5-8): 365-384, DOI: 10.1080/00222933.2022.2071179, URL: http://dx.doi.org/10.1080/00222933.2022.2071179

Ophioderma occultum sp. nov. (Figures 1 – 3; Table 1) Ophiura panamensis. – Ives 1889: 76–77 (partim) Ophioderma panamense. – Ziesenhenne (1955): 194, 197 (partim). – Brusca and Smith (1973): 318, 320, figs 12.15–12.16 (partim). – Brusca 1980: 407, fig. 26.15a–b (partim). – Kerstitch and Bertsch (2007): 113 (partim) Ophiura teres. – Ives (1889): 77 (partim) Material examined Type material. Holotype: ICML-UNAM 18429; Mexico, Gulf of California, Baja California Sur, Punta Pichilingue (24.285°N, 110.334°W); 0.5–2.5 m; sand under rocks; 7 November 2019; coll. K.J. Humara-Gil, R. Granja-Fernández, B. Maya-Alvarado, A. Hernández-Morales, M.A. Medina-López; preserved in 96% ethanol; COI sequence: OK076949 (GenBank); 16S sequence: OK078012 (GenBank). Paratypes: ICML-UNAM 18430, 5 spec.; same data as holotype; preserved in 96% ethanol (1 used for DNA analysis, labelled as ‘OO4’; COI sequence: OK076948 [GenBank]; 16S sequence: OK078011 [GenBank]). ICML-UNAM 18431, 3 spec.; same data as holotype; dry. ICML-EMU 12867, 5 spec.; same data as holotype; preserved in 96% ethanol. ICML-EMU 12868, 3 spec.; same data as holotype; dry. Additional material. See the Supplemental material. Diagnosis Radial shields and adoral shields covered with granules. DAPs divided into two (typically) or more irregular pieces for about 2/3 of the arm. Colour pattern dark grey to brown (fixed specimens), or dark olive green to brown (in vivo specimens); arms with subtle lighter transverse bands, and parallel longitudinal white bands over some median and distal arm segments. Description Holotype. DD = 15.9 mm, AL = 49.3 mm. Disc nearly rounded, covered with rounded granules slightly separated from each other; size of the granules increasing from the disc centre towards the periphery. Dorsal disc granule density 52 per mm2. Radial shields covered with granules (Figure 1 (a)). Interradii covered with granules similar to those on the dorsal side. Four genital slits per interradius. Proximal genital slits oval, in contact with the distal section of the oral shield and the 1st LAP; reaching up to the 2nd VAP. Distal genital slits oval, twice longer than proximal genital slits, placed between 5th and 7th arm segments; surrounded by granules and, only next to the arm, imbricated scales (Figure 1 (b)). Oral shields broader than long, subtriangular; proximal edges convex forming a rounded apex; rounded lateral edges; straight distal edge. Madreporite with oval, central depression. Adoral shields covered with scattered granules, larger than those on the interradii. Jaws with 7–8 oral papillae: LyOs two times longer than broad, angled upwards; AdShSp the largest, subquadrangular; 2°AdShSp similar to AdShSp, smaller; LOPas 3–4 (rarely two), conical, pointed and elongated, slightly separated; IPa similar in shape to LOPas; TPa 1–2 at the apex of jaw, robust and pointed. Teeth, five: vT robust, subtriangular, larger than TPa; median teeth quadrangular; the dorsalmost the smallest, triangular and pointed. One OPRSp at each side of jaw, large, prominent. Oral plates covered with elongated, separated granules, larger than those on the adoral shields (Figure 1 (b–c)). Five arms flattened, tapering distally; one cut for molecular analysis, one complete probably regenerated from the midsection, one regenerating close to tip, two broken near tip. Dorsal arm base covered with granules and scales located laterally over the first three DAPs (Figure 1 (d)). DAPs wider than long, divided typically into two and up to five (only one DAP in all five arms) irregular pieces in approximately 2/3 of the arm; the number of pieces decreases distalwards (Figure 1 (d–f)). Distalmost DAPs entire, small, trapezoidal (Figure 1 (f)). First VAP small, 1.5 as wide as long, with rounded edges (Figure 1 (b)). Subsequent VAPs quadrangular, as long as wide; proximal edge straight, distal edge convex (Figure 1 (g–h)). Distalmost VAPs pentagonal, longer than wide (Figure 1 (i)). A pair of pores are visible between the two proximalmost VAPs in all five arms (Figure 1 (b)). LAPs conspicuous, wider than long. LAP with up to eight arm spines, rarely nine. Arm spine sequence of the longest arm (right side): first 10 segments, 2, 2, 3, 3, 4, 4, 5, 6, 8, 8; 11th– 20th, eight arm spines; 21st–30th, 7–8; 31st–40th, 6–8; 41st–50th, 6–8; 51st–60th, 5–6; 61st– 70th, 3–5; 71st–75th, two. Arm spines conical with blunt tips, length 2/3 of LAP. Dorsalmost arm spine the shortest; ventralmost the longest and more robust, in contact with abradial tentacle scale of the following segment (Figure 1 (d–j)). Two tentacle scales; adradial tentacle scale oval, elongated, 2/3 the length of VAP; abradial tentacle scale shorter, 2/3 the length of adradial one, subtriangular (Figure 1 (g–h)). General colouration dark grey (specimen in ethanol; Figure 1 (k)). Dorsal side: disc dark grey, with scattered white granules (Figure 1 (a)). Arms grey with subtle lighter transverse bands; 1–3 adjacent DAPs and LAPs with a pair of parallel white blotches every 3–15 segments in the median and distal arm sections, macroscopically perceived as parallel longitudinal white bands (Figure 1 (e, j–k)). Ventral side: interradii dark grey with scattered white granules (Figure 1 (b)). Jaws and arms light grey, oral papillae beige (Figure 1 (b–c)). Some VAPs with a white spot located randomly (Figure 1 (b, h)). LAPs grey, some with a dorsal white blotch. Dorsalmost arm spines grey, becoming clearer to the ventralmost side, with a white spot on the tip (Figure 1 (j)). Paratype and non-type variations Specimens in the type series varied from 3.7 to 21.1 mm in disc diameter size. The smallest specimen (DD = 3.7 mm, Figure 2) presented a disc granule density of 329 per mm2 (Figure 2 (a)). Its jaws were covered with granules, including oral shields (Figure 2 (b–c)). Only one oral shield, presumably the madreporite, was partially uncovered; it presented a dark grey colour and a minute depression on the centre (Figure 2 (b)). This is consistent with what Ziesenhenne (1955) observed in O. panamense (DD = 4 mm), in which the first oral shield to be uncovered was the madreporite. Distal genital slits only presented granules (Figure 2 (b)), in comparison with those of larger specimens which also presented scales (Figure 1 (b)). Similarly, the specimen presented only granules on the dorsal arm base, extending over two arm segments (Figure 2 (d)). All the DAPs were entire and surrounded by granules (Figure 2 (d–e)); distal ones were completely covered with granules (Figure 2 (f)). Some proximal VAPs were partially covered with granules (Figure 2 (b)), the rest were naked (Figure 2 (g–i)). All the LAPs were partially covered with granules and presented up to five arm spines (Figure 2 (j)). The presence of granules on the disc, including jaws, and arms (DAPs, VAPs, LAPs) is common among Ophioderma juveniles (e.g. Ophioderma brevicaudum Lütken, 1856, Clark 1939; O. hendleri Granja-Fernández et al. 2020; O. panamense Ziesenhenne 1955; Ophioderma rubicundum Lütken, 1856, Hendler 2018). One arm segment presented three tentacle scales. As individuals became larger (DD = 5.7 mm), some scales on the dorsal arm base and on the distal genital slits were visible; oral shields started to uncover but still presented some granules, and the maximum number of arm spines increased to six. A specimen of DD = 11.2 mm showed oral shields totally naked, but less elongated than those of the holotype, and its DAPs were mostly entire as in smaller specimens. This specimen, as well as the holotype (DD = 15.9 mm), presented 1–6 abnormal arm spines in some segments along the arms; these were twice as wide as typical and variable in shape (e.g. bifurcated, flattened), mainly present in the proximal and median section of the arm. A specimen of DD = 13.3 mm presented most DAPs divided into two pieces; some median and distal DAPs were entire. Specimens of similar sizes to the holotype or larger (DD = 15.1– 21.1 mm) presented a maximum of nine arm spines, and sporadically three tentacle scales in 1–3 arm segments (Figure 3 (e)). One specimen (DD = 17.5 mm) presented some median DAPs entire, which were 2.5 times as wide as long. Regarding colouration, the extent of white granules on the dorsal disc varied in every specimen; they could be: (1) a few scattered on the disc as in the holotype (Figure 1 (a)), (2) arranged in larger groups at the margin and centre of the disc (Figure 2 (a)), or (3) not present at all; the smallest specimens presented a greater extension of white granules on the dorsal disc (Figure 2 (a)). Some specimens presented white-spotted oral shields (Figure 3 (b)). Additionally, some variations were noticed in non-type specimens (DD sizes up to 26.7 mm): (1) 16 specimens presented 1–3 partially naked radial shields (Figure 3 (a)); (2) one specimen presented white oral shields with a grey madreporite (Figure 3 (c)); (3) 13 specimens (DD = 20.8–25.5 mm) presented up to 11 arm spines; (4) one large specimen (DD = 26.7 mm) presented few granules over the six proximalmost DAPs (Figure 3 (d)); (5) eight specimens (DD = 12.9–18.5 mm) presented some abnormal arm spines such as those observed in the holotype and one paratype (Figure 3 (f)); (6) some fixed specimens presented a brown general colouration instead of dark grey (Figure 3 (g)), while live specimens showed a dark olive green to brown colour (Figure 3 (h–i)); and (7) the parallel white blotches on the arms of some specimens were present in up to 18 contiguous DAPs and LAPs. Of the variations observed in O. occultum sp. nov., features such as partially uncovered radial shields, granules on DAPs of large specimens, abnormal arm spines, and arm segments with three tentacle scales are considered rare, as they were observed only in Habitat and distribution Ophioderma occultum sp. nov. is distributed in shallow waters, from intertidal to 6 m depth, and is typically found in rocky reefs and tide pools, on sediment under mediumsized rocks. The species has only been found in the northern Mexican Pacific, particularly in the Gulf of California (in the States of Baja California, Baja California Sur, and Sonora) and islas Revillagigedo (isla Roca Partida). Its northernmost record corresponds to Polilla, Bahía de los Ángeles (29°N) and the southernmost to bahía Eclipse, isla Roca Partida (19°N). Etymology The species name occultum (-us, -a) is a Latin singular neuter adjective in the nominative case, meaning ‘hidden’. Ophioderma occultum sp. nov. has been collected and recorded since the nineteenth century in the north of Mexico; however, it was mistakenly considered a colour phase of O. panamense. It remained hidden in plain sight, hence its name. Remarks Ophioderma occultum sp. nov. most resembles O. panamense, with which it has been confused for over a century (Ives 1889; Ziesenhenne 1955; Brusca and Smith 1973; Brusca 1980; Kerstitch and Bertsch 2007). Both species present covered adoral shields, scales on the base of the arms, scales and granules ornamenting the distal genital slit, and banded arms. However, O. panamense has naked radial shields, DAPs usually entire, can display different colours on the dorsal disc (green, brown, grey mottled with yellow, orange, or pink), and its bands on the arms are conspicuous (Figure 4 (c); Table 1; Granja-Fernández et al. 2014, 2020), while O. occultum sp. nov. presents radial shields usually covered with granules, DAPs divided into two (typically) or more pieces, subtle lighter bands on the arms, and characteristic parallel white blotches on some DAPs and LAPs in the median and distal arm sections, giving the appearance of parallel longitudinal white bands. Some authors noticed the aforementioned characters but considered them intraspecific variations of O. panamense. Ives (1889, 76–77) mentioned the following: “Mr. Lockington records a variety with a brown disk and olive green, arms without bands except at the tips” and “The darkest variety of O. teres closely resembles the darkest variety of O. Panamensis [sic]. In both forms some of the upper arm-plates of the outer portion of the arm have white markings, which form segments of two broken parallel longitudinal lines, one on each side of the arm. Each segment occupies one or more plates and is separated from the next segment by an also variable number of plates without any such markings”. This coincides with the colour pattern observed in O. occultum sp. nov. Likewise, Ziesenhenne (1955, 194) mentioned that O. panamense showed one colour combination In which the disk is brown to olive and the arms greenish, with the arms banded distally with white... Some specimens have broken upper arm plates.... The majority of the specimens of this color phase have concealed, or partially concealed, radial shields. All of the above are now considered diagnostic characters of O. occultum sp. nov. Moreover, O. panamense and O. occultum sp. nov. differ in their distributions; the former is widely distributed from southern USA to Peru (Granja-Fernández et al. 2020), while O. occultum sp. nov. is restricted to the northern Mexican Pacific. In the Gulf of California both species appear to be the most common and abundant Ophioderma, along with O. hendleri. However, O. occultum sp. nov. is most often found in shallower waters (i.e. intertidal and tide pools; RGF, KJHG pers. obs). The new species was also misidentified as O. teres in the scientific collections and literature (Ives 1889). Since the holotype of O. teres is lost, we based our comparisons on the original description of the species, as well as on a specimen identified by Lyman as O. teres (MCZ OPH-112). Although this specimen is not a topotype (i.e. it is not from Panama, the type locality of O. teres, but from Acapulco, Mexico), it agrees with the description of O. teres and was included as additional material in Lyman’s first descriptions of the species (Lyman 1860, 257, 1865, 38). Ophioderma teres differs from O. occultum sp. nov. in having DAPs divided into multiple pieces (up to five pieces), rounded arms, and a speckled colour pattern on disc and arms (Figure 4 (j); Table 1). Confusions between the two species may arise from the fact that both present divided DAPs, as well as a misinterpretation of O. teres speckles on the arms (Figure 4 (j)) as the white blotches present in the median and distal arm sections of O. occultum sp. nov. Differences among O. occultum sp. nov. and all its congeners from the Eastern Pacific are summarised and illustrated in Table 1 and Figure 4. Genetic delimitation of the species COI sequences obtained in this study had a total length of 680 bp; however, they were cut to align them with those retrieved from BOLD and GenBank, resulting in the analysis of 426 bp. Of these, 305 (71.60%) sites were conserved and 121 (28.40%) were variable, all parsimony informative. On the other hand, 16S sequences varied from 489 to 500 bp, and the alignment presented several indels. The latter were removed, and 454 bp were analysed. In this case, 328 (74.25%) sites were conserved and 126 (27.75%) were variable, of which 123 (27.09%) were parsimony informative. DD = 21.1 mm): (d) close-up of a jaw; (e) dorsal arm. Ophioderma peruanum (holotype: CZA-363, DD = 32.5 mm): (f) portion of dorsal disc and arm. Ophioderma sodipallaresi (holotype: ICML-UNAM 3.24.3, DD = 19.1 mm): (g) portion of dorsal disc and arm; (h) close-up of a jaw; (i) distal genital slit. Ophioderma teres (non-type specimen: MCZ OPH-112, DD = 24.8 mm): (j) portion of dorsal disc and arm. Ophioderma teres unicolor (holotype: MCZ OPH-114, DD = 30 mm): (k) portion of dorsal disc and arm. Ophioderma vansyoci (holotype: LACM 90 – 391.1, DD = 31 mm): (l) portion of dorsal disc and arm; (m) close-up of a jaw. Ophioderma variegatum (lectotype: NHMD-107680, DD = 12.4 mm): (n) portion of dorsal disc and arm; (o) close-up of a jaw. See the Supplemental material for more information. The topology of the trees was consistent between the two genes (COI, 16S) and the two methods (ML, NJ). The main clade grouped the species of Ophioderma, followed by a subclade grouping O. cf. teres unicolor, O. panamense and O. occultum sp. nov., and another subclade grouping the two latter species; both presented high bootstrap values (81–100). Sequences of O. occultum sp. nov. formed a well-supported clade (bootstrap values: 93/100) for both molecular markers with ML and NJ, separating it from the rest of the species. Particularly for COI, BOLD sequences included in the analysis were grouped with O. occultum sp. nov., which confirmed the hypothesis that those specimens were O. occultum sp. nov. and not O. panamense, as suspected based on photographs. According to the analysed data, the sister taxon of O. occultum sp. nov is O. panamense, whereas O. hendleri is the most distantly related to it (Figure 5). The estimated mean genetic distances among species were 8.76–19.95% for COI, and 3.16–22.69% for 16S. The lowest genetic distances were recorded between O. occultum sp. nov. and O. panamense, and the greatest between O. occultum sp. nov. and O. fallax (COI) and O. panamense and O. fallax (16S; Table 2).

Ophiotreta eximia (Koehler, 1904) Figs 15–16 Ophiacantha eximia Koehler, 1904: 116–117, pl. 21 figs 3–5. Ophiacantha dilecta Koehler, 1904: 117–118, pl. 22 figs 3–4. Ophiotreta eximia – H.L. Clark 1915: 216. — Koehler 1922a: 70–71, pl. 8 figs 5–6, pl. 93 fig. 7. — O’Hara & Stöhr 2006: 55–56, fig. 4e–g. Ophiotreta dilecta – H.L. Clark 1915: 216. — Koehler 1922a: 71. Material examined CHINA • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°35.80′ N, 111°02.00′ E; depth 1750 m; 3 Apr. 2018; collection event: stn SC022; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB SW0030. Description (IDSSE EEB-SW 0030) MEASUREMENTS. Disc diameter 11.9 mm, arm width 3.0 mm. DiSC. Circular, dorsal side covered by overlapping scales with one or mostly two spines (Fig. 15A–B). Disc spines tall, 0.4–0.6 mm high, 10–11 times as high as wide, slender, thorny, with two to three small, non-flaring terminal thorns (Fig. 15C–G). Few disc spines scattered on first dorsal arm segment (Fig. 15E). Radial shields covered by disc scales and skin (Fig. 15A, E). Ventral disc completely covered by disc spines, two small disc spines at ventralmost margins of three oral shields. Genital slits conspicuous, extending from oral shield to periphery of disc (Fig. 15B–F). Oral shield much wider than long, broadly triangular, with obtuse proximal angle and lobed or convex distal edge. Adoral shield long and narrow, mostly not separated. Adoral shields enclosing proximal edges of oral shield and separating it from first lateral arm plate, reaching just beyond lateral angle of oral shield (Fig. 15F). Jaws longer than wide. Cluster of papillae on jaw with three to five large, pointed, spiniform tooth papillae on dental plate and two rows of pointed papillae on apex of jaw (on oral plates), with large, pointed tip, five to seven lateral oral papillae and distalmost two flat and enlarged (Fig. 15F). ARMS. Dorsal arm plates as long as wide, fan-shaped, triangular with straight proximal end, slightly curved distal margin, covered with minute spines and consecutive plates completely separated (Fig. 15J). Ventral arm plates pentagonal, as wide as long except on first one to two arm segments, straight obtuse triangular proximal end, distal margin truncated to concave, along arm plates thickened distalwards, consecutive plates well separated (Fig. 15H–I). Lateral arm plates meeting above and below (Fig. 15H). 10–12 arm spines at each lateral arm plate; five to six upper arm spines four to six arm segments in length, smooth and meeting across dorsal midline (Fig. 15G); five to six lower arm spines short, two to three shortest, half arm segment in length, thorny (Fig. 15K). Lowermost arm spine on lateral arm segments slightly flattened with curved shape and straight, elongated thorns along tip of curved surface (Fig. 15H). One elongated, large tentacle scale with thorny apex, longer than ventral arm plate but becoming narrow and pointed distalwards on arm (Fig. 15K). First arm segment with two tentacle scales covering tentacle pore (Fig. 15F). COLOR. When alive, grey to whitish on disc and arms, mouth region and spines light brown (Fig. 15A–B). OSSiCLE MORPHOLOGY. Arm spine articulations well developed and placed at small angle in relation to distal edge of lateral arm plate, separated from proximal part of plate by wavy ridge. Ventral and dorsal articular lobes fused into a single volute-shaped articular structure (with sigmoidal fold, see Martynov 2010), dorsal lobe perforated by small holes, ventral lobe smooth and non-perforated (Fig. 16A). Large muscle opening and small nerve opening, but dorsalmost arm spine articulation without sigmoidal fold and ventral ones entire but connected to main part of lateral arm plate by short ridge (Fig. 16A–B). Vertebrae with long zygospondylous articulation, distally abruptly truncated, dorsal median furrow moderately expressed and podial basins long and large (Fig. 16C–G). Remarks The disc diameter of our specimen is within the range of the type specimens (11–21 mm). Koehler (1904) divided these specimens according to morphological variation of the arm plate and arm spines, but these variations fall within the morphological type series of O. eximia, and little morphological variation is expressed in the number of arm spines, height of the disc spines and number of oral papillae. The size of the specimens affects the morphological variation in O. eximia such as the number of oral papillae, the number of tentacle scales on the first arm segment and disc spine length. Due to these morphological variations, it is rather difficult to distinguish species of Ophiotreta. Ophiotreta matura Koehler, 1904 is quite similar to O. eximia , but differs in having stouter disc spines with flared terminal thorns, thornier upper arm spines and arm plates and hook-shaped thorny ventralmost arm spines (O’Hara & Stöhr 2006). The specimen in the present study showed a unique morphological feature in two small thorny spines located at the ventral margin of the oral shields directly proximal to the genital slits (Fig. 15F). Distribution 724–1893 m depth. South China Sea, New Zealand, Makassar Strait, Sulu Sea, Molucca Sea, Flores Sea, Coral Sea and Tasman Sea (O’Hara & Stöhr 2006; OBIS 2021). Genus Ophiopristis Verrill, 1899, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 31-34, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Koehler R. 1904. Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. Siboga Expeditie 45 A: 1 - 176.","Clark H. L. 1915. Catalogue of recent ophiurans, based on the collection of the Museum of Comparative Zoology. Memoirs of the Museum of Comparative Zoology at Harvard College 25 (4): 164 - 376.","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","O'Hara T. D. & Stohr S. 2006. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Richer de Forges B. & Justine J. - L. (ed.) Tropical Deep-Sea Benthos 24: 33 - 141. Museum national d'histoire naturelle, Paris.","Martynov A. 2010. Reassessment of the classification of the Ophiuroidea (Echinodermata), based on morphological characters. I. General character evaluation and delineation of the families Ophiomyxidae and Ophiacanthidae. Zootaxa 2697 (1): 1 - 54. https: // doi. org / 10.11646 / zootaxa. 2697.1.1","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Asteronyx luzonicus Döderlein, 1927 Figs 4–6 Asteronyx luzonicus Döderlein, 1927: 64, pl. 7 figs 4–5, 6a–d. Asteronyx luzonicus – Baker et al. 2018: 7–8, figs 4–5. Material examined CHINA • 1 spec.; South China Sea, SE of Hainan Island, seamount; 18°31.76′ N, 112°40.56′ E; depth 1167 m; 27 Jun. 2019; collection event: stn SC002; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198757, MZ 203265; IDSSE EEB-SW0003 • 1 spec.; same collection data as for preceding; depth 1162 m; 8 Jul. 2019; collection event: stn SC002; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0032. Description (IDSSE EEB-SW 0003) MEASUREMENTS. Disc diameter 13.5 mm. DiSC. Flat, pentagonal. Entire dorsal disc covered by smooth, transparent, naked skin, but some small calcified scales between radial shields. Skin on center of dorsal disc becoming mesh-like and less smooth than at periphery of disc. Radial shields narrow, elongate, separate, covered by skin and extending to near disc center, but not meeting in center (Fig. 4A). Ventral (oral) surface of disc also covered by smooth skin (Fig. 4B). Oral shields slightly triangular. Adoral shield large, wider than long and slightly concave at distal margin, bordering proximal end of a depressed area near genital slit. Two tooth papillae, large and pointed, three smaller pointed lateral oral papillae, teeth also pointed. Two small, short, well separated genital slits in each ventral interradius (Fig. 4C–D). ARMS. Simple, similar in size and length, five in number, with no abrupt change in width proximally, gradually tapering toward arm tip. No dorsal arm plates, arm covered with smooth translucent skin, leaving vertebrae visible (Fig. 4E). Ventral and lateral arm plates concealed by thick skin but slightly visible on proximal arm (Fig. 4F). Lateral arm plates meet at ventral midline, spines at ventrolateral margin extending onto ventral surface (Figs 4F–G, 5A–B). Starting from first free arm segment beyond disc, first two to three arm segments without spines at tentacle pores (Fig. 4B–C); third to fourth arm segments with one or two short arm spines, becoming hook-shaped or with one secondary tooth (Fig. 4C). Following tentacle pores with two to five hook-shaped arm spines and only uppermost arm spine elongated to simple hook shape, but ventralmost spines with one secondary tooth (Fig. 5D). Length of all arm spines decreasing to approximately half length of corresponding arm segment in middle of arm. On distal third of arm, arm spines half as long as corresponding arm segment and transforming into hooks without secondary tooth, except ventralmost arm spine. Ventralmost arm spine becoming cylindrical, blunt with thorny tip, as long as one arm segment (Fig. 5A–F). Tube foot elongate, cylindrical, slender, as long as an arm segment and positioned close to ventralmost arm spine (Fig. 5A–C). COLOR. Dorsal disc light brown in center, naked skin between radial shields darker, radial shields whitish brown; ventral interradial areas light brown; arms whitish brown above and below (Fig. 4). OSSiCLE MORPHOLOGY. Lateral arm plate curved around vertebrae, bearing five spine articulations, each with small muscle opening, but lacking a separate nerve opening (Fig. 6A–C). Arm spine articulations at distal edge of lateral plate, raised outwards, pointing distalwards. A depression on inner side of lateral arm plate (Fig. 6B). Vertebrae with streptospondylous articulation, ventral side with a longitudinal groove along midline and no oral bridge (Fig. 6D–H). Remarks The here examined specimens were collected on a deep-sea seamount, attached to a gorgonian. Asteronyx luzonicus was first described by Döderlein (1927) from the Philippines. However, there are few published descriptions of A. luzonicus (Baker et al. 2018) and the species has not been imaged well before. Döderlein (1927) mentioned an elongated, slender ventralmost arm spine, as long as an arm segment, parallel to the longitudinal arm axis, as a distinguishing morphological feature of A. luzonicus, because in other species of Asteronyx, the ventralmost spine is usually placed transversally to the longitudinal axis of the arm and often reaches twice the length of an arm segment. Dried specimens of A. luzonicus are particularly strikingly dark and a main distinguishing morphological feature of A. luzonicus is the presence of black spots on the disc of sexually mature specimens (Baker et al. 2018). Specimens from our collection were not sexually mature and only had darker skin on both the dorsal and ventral disc, but they concur with a Baker et al. (2018) in the calcified scales. Recent studies on species of Asteronyx suggested that features of the dorsal disc surface, as well as the position and length of the genital slit may be important characters to distinguish the six species in this genus (Okanishi et al. 2018). Döderlein did not describe the dorsal disc surface and mentioned few morphological characters to distinguish his new species from other species in the genus Asteronyx, i.e., in characters of the tentacle scale and darker disc spots in sexually mature specimens. Specimens of Asteronyx in our collection are immature but similar in size. Therefore, a comprehensive morphological analysis can be used to distinguish A. loveni from A. luzonicus such as: hook-shaped arm spines with at most one secondary tooth along the arm in A. luzonicus, whereas A. loveni has hook-shaped arm spines with more than one secondary tooth (Figs 2F, 4F, 5); in A. luzonicus the dorsal disc surface is flatter than in A. loveni and becoming rough, mesh-like in the center (Figs 2A, 4A); the first two to three arm segments in A. luzonicus have only a tentacle foot and no arm spine, but in A. loveni only the first arm segment is without a single spine (Figs 2B, 4B). The ventralmost arm spine is as long as one arm segment, cylindrical, tapered, with a blunt, thorny tip (Fig. 5H–J). Asteronyx reticulata Okanishi, Martynov & Fujita, 2018 is similar to A. luzonicus, but differs in having mesh-like skin on its ventral disc (Okanishi et al. 2018). Distribution 109–2963 m depth. South China Sea, Sibuyan Sea, Samar Sea, Bohol Sea, East China Sea, Andaman Sea, Southern Mozambique (Baker et al. 2018). Family Euryalidae Gray, 1840 Genus Asteroschema Örsted & Lütken in Lütken, 1856, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 14-18, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Doderlein L. 1927. Indopacifische Euryalae. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse 31 (6): 1 - 106.","Baker A. N., Okanishi M. & Pawson D. L. 2018. Euryalid brittle stars from the international Indian Ocean Expedition 1963 - 64 (Echinodermata: Ophiuroidea: Euryalida). Zootaxa 4392 (1): 1 - 27. https: // doi. org / 10.11646 / zootaxa. 4392.1.1","Okanishi M., Sentoku A., Martynov A. & Fujita T. 2018. A new cryptic species of Asteronyx Muller and Troschel, 1842 (Echinodermata: Ophiuroidea), based on molecular phylogeny and morphology, from off Pacific coast of Japan. Zoologischer Anzeiger 274: 14 - 33. https: // doi. org / 10.1016 / j. jcz. 2018.03.001"]}

Ophiopristis shenhaiyongshii sp. nov. urn:lsid:zoobank.org:act: 31D1CA52-EBB3-4BCB-9327-BF43B085AB6D Figs 17–19 Diagnosis Disc spines rugose with two to three small terminal thorns on truncated tip or minutely bifurcated tip. Radial shields with distal end exposed. Oral shield distal edge with series of thick, rugose thorny spines. Ventralmost arm spine with longer thorns at lateral edge, distally with some ventrally directed thorns. Tentacle scales oval and pointed, two on the first three segments, thereafter one large scale. Etymology The specific name is dedicated to the manned submersible vessel ‘Shenhaiyongshi’, which collected the specimen. Material examined Holotype CHINA • South China Sea, SE of Zhongsha Islands, seamount; 13°23.98′ N, 114°51.50′ E; depth 1360 m; 23 Sep. 2020; collection event: stn SC012; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198776; IDSSE EEB-SW0022. Description MEASUREMENTS. Disc diameter 6.3 mm, base of arm width 1.5 mm. DiSC. Pentagonal and covered with translucent, perforated, rounded, overlapping scales bearing one or two tall spines (Fig. 17A–C). Disc spines 0.4 to 0.8 mm high, glassy, hollow, rugose with two to three small terminal thorns on truncated tip or minutely bifurcated tip. Disc spine height and shape change from center to periphery of disc (Fig. 17C–G). Central disc spines short (0.3–0.4 mm high), smooth, with one to two terminal thorns. Peripheral disc spines and around radial shields taller (0.6–0.8 mm high), strongly rugose, with subterminal tooth and two to three terminal thorns on truncated or bifid tip (Fig. 17D–E). Edge of disc periphery and distal margin of radial shield with few short thorny stumps with crown of two spinelets (Fig. 17E). Proximal ends of radial shields largely covered by disc scales, distal ends exposed, triangular, pair of shields widely separated (Fig. 17G). Ventral disc covered by scales with spines, but shorter and less dense than a dorsal disc. Oral shield wider than long, triangular with obtuse proximal angle, curved lateral margins, rounded to truncated distal edge with series of short, thick, rugose, thorny-tipped spines (Figs 17H, 18A–B). Adoral shield long, with straight lateral margin, but near first ventral arm plate slightly curved, pair of shields meeting proximally (Fig. 18A). Adoral shields enclose proximal edges of oral shield, curving to lateral plate of first arm segment, separating oral shield from arm. Jaw slightly longer than wide, opening of second tentacle pore superficial (Fig. 18A). Mostly two (one jaw has three) small, pointed tooth papillae on apex of jaw, below large pointed single column of teeth. Up to five finger-like, tapering, pointed lateral oral papillae. Two enlarged and flattened, pointed oral papillae arising from adoral shield and separated from other oral papillae, probably adoral shield spines (Fig. 18A). Genital slits conspicuous and extending from oral shield to periphery of disc (Fig. 18B). Oral surface covered by transparent integument, partially obscuring oral frame beneath, but only visible in live wet condition (fresh) (Fig. 17H). ARMS. Five moniliform arms, with glassy plates (Fig. 18C–F). Dorsal arm plates separate, as long as wide, bell-shaped, with straight proximal end, slightly wavy distal margin covered with minute spines (Fig. 18C–D). Ventral arm plates as wide as long, with convex distal end, slightly obtuse proximal end, lateral edges concave, well separated along arm, axe head-shaped proximalmost arm plates (Fig. 18E–F). Lateral arm plates meeting above and below. Six arm spines. Three dorsal spines, three arm segments in length, laterally compressed, thorny, lateral margins with row of widely spaced, tall sharp thorns, apex truncated or bluntly rounded (Fig. 18H). Three ventral arm spines, one to two arm segments in length, laterally compressed, dense row of shorter, sharp thorns, apex truncated or blunt (Fig. 18H). Ventralmost arm spines with longer thorns at lateral edge, distally with some ventrally directed thorns, but without true hook-shape (Fig. 18H). Tentacle pores large, on up to three proximalmost segments with two scales, oval to pointed, one on lateral arm plate, other on ventral plate. Beyond third segment with single large tentacle scale on lateral plate, covering pore (Fig. 17A, E–F). COLOR. In dried specimen glassy, darker in center but rest of specimen white and arm spines transparent (Fig. 17A–B). When alive, disc glassy dark brown, arms creamy white and arm spines transparent (Fig. 17G–H). OSSiCLE MORPHOLOGY. Arm spine articulations well developed, volute-shaped, on protruding distal part of lateral plate with porous stereom, delimited from smooth middle part of lateral plate by thin wavy edge. Proximal edge of spine articulation entire, but connected with main part of lateral arm plate by short ridge. Arm spine articulation with large muscle opening and small nerve opening (Fig. 19A–C). Dorsal arm spine laterally compressed, thorny, several longitudinal rows of perforations with widely spaced, tall thorns, apex truncated (Fig. 19D). Vertebrae with zygospondylous articulation, with moderately expressed narrow dorsal furrow, distally abruptly truncated, and podial basins moderate in size (Fig. 19E–I). Ambulacral furrow with greatly widened middle, without oral bridge (Fig. 19G). Remarks The genera Ophiopristis and Ophiotreta are at present poorly delimited from each other. On the phylogenetic tree in Christodoulou et al. (2019) they are both polyphyletic and several species may have to be reassigned to other genera in a future taxonomic revision. Assigning our new species to either of them is therefore difficult. We compared the new species to the type species of both genera, Ophiotreta lineolata (Lyman, 1883) and Ophiopristis hirsuta (Lyman, 1875). Both are present on the tree in Christodoulou et al. (2019), in different clades, suggesting that they indeed represent two different genera. According to the original description, O. lineolata has a cluster of tooth papillae, a dense dorsal disc cover of coarse grains intermingled with a few short spines, the radial shields are obscured by granules and there are 8–9 translucent, almost smooth arm spines and a single large tentacle scale on all but the first pore (Lyman 1883). Ophiopristis hirsuta has elongated jaws with seven spiniform lateral oral papillae and no tooth papillae (although the illustration seems to show two tooth papillae), the dorsal disc is covered by short, fine spines (which on the illustration look rather long), the distal ends of the radial shields are exposed and swollen, the six arm spines are flattened, glassy and strongly serrated, and there are two large tentacle scales (Lyman 1875). There was also a striking size difference, with O. lineolata having a disc diameter of 18 mm and O. hirsuta just 3.7 mm. Ophiopristis shenhaiyongshii sp. nov. shares the disc spines, distally exposed radial shields, few or no tooth papillae, flat serrated arm spines and the small size with Ophiopristis hirsuta and differs from Ophiotreta lineolata in all respects. Hence, we propose to assign it to the genus Ophiopristis due to its similarity to the generic type species. It can be delimited from other species currently assigned to Ophiopristis as follows: Ophiopristis dissidens (Koehler, 1905) is similar to O. shenhaiyongshii sp. nov. by having exposed distal radial shields, the oral shield wider than long and widely separated ventral and dorsal arm plates, but differs by having smooth disc spines, two to three tentacle scales until the twelfth segment and a brown line running discontinuously along the dorsal surface of each arm (O’Hara & Stöhr 2006). Ophiopristis gadensis Rodrigues et al., 2011 is similar to O. shenhaiyongshii sp. nov. by having exposed radial shields, rugose disc spines with two or three thorns, the oral frame covered by a transparent integument and glassy arm plates and arm spines, but differs by having rounded pentagonal oral shields, contiguous dorsal and ventral arm plates, and two to three tentacle scales along the arm (Rodrigues et al. 2011). Ophiopristis shenhaiyongshii sp. nov. differs from most species of Ophiopristis by having a series of thorny spines on the distal margin of the oral shield. This character is only shared by O. luctosa (Koehler, 1904) and O. procera (Koehler, 1904), and both species were first recorded from Indonesian waters. Ophiopristis luctosa differs from O. shenhaiyongshii sp. nov. by having long, thin, sharp, hollow, smooth disc spines, the radial shield largely obscured, small rounded oral papillae, ventral arm plates twice as long as wide, rectangular and contiguous, the ventralmost spine with a hook-like appearance and one oval tentacle scale, and a yellow color with a few broad brown bands on the arms (Koehler 1904; O’Hara & Stöhr 2006). Ophiopristis procera differs from O. shenhaiyongshii sp. nov. by having completely concealed radial shields, the ventral arm plate twice as long as wide, rectangular and contiguous, the first pair of tentacle pores covered by tentacle scales variable in size and overlapping, and the following pairs only covered by one large, elongated oval scale, equal to the length of an arm segment. Ophiopristis shenhaiyongshii sp. nov. shares similar disc spine and arm spine characteristics with O. procera (Koehler 1904). Distribution South China Sea (1360 m). Near Zhongsha Islands, found on a deep-sea seamount. Family Ophiacanthidae Ljungman, 1867 Genus Ophientrema Verrill, 1899, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 34-39, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Christodoulou M., O'Hara T. D., Hugall A. F. & Arbizu P. M. 2019. Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology 29 (22): 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012","Lyman T. 1883. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Carribbean Sea (1878 - 79), and on the east coast of the United States, during the summer of 1880, by the U. S. coast survey steamer \" Blake \", commander J. R. Bartlett, U. S. Bulletin of the Museum of Comparative Zoology 10 (6): 227 - 287.","Lyman T. 1875. Zoological Results of the Hassler Expedition. 2. Ophiuridae and Astrophytidae. Illustrated Catalogue of the Museum of Comparative Zoology at Harvard College 8 (2): 1 - 34.","Koehler R. 1905. Ophiures de l'expedition du Siboga. Part 2. Ophiures littorales. Siboga Expeditie 45 B: 1 - 140.","O'Hara T. D. & Stohr S. 2006. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Richer de Forges B. & Justine J. - L. (ed.) Tropical Deep-Sea Benthos 24: 33 - 141. Museum national d'histoire naturelle, Paris.","Rodrigues C. F., Paterson G. L. J., Cabrinovic A. & Cunha M. R. 2011. Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic). Zootaxa 2754 (1): 1 - 26. https: // doi. org / 10.11646 / zootaxa. 2754.1.1","Koehler R. 1904. Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. Siboga Expeditie 45 A: 1 - 176."]}

Ophientrema scolopendrica (Lyman, 1883) Figs 20–22 Ophiacantha scolopendrica Lyman, 1883: 259. Ophiacantha leucosticta H.L. Clark, 1911: 235. Ophientrema leucosticta – Matsumoto 1917: 111. Ophientrema leucostictum – H.L. Clark 1911: 217. — Koehler 1922a: 85, pl. 8 figs 1–4, pl. 94 fig. 1. Material examined CHINA • 1 spec.; South China Sea, E of Hainan Island, seamount; 18°30.14′ N, 112°49.62′ E; depth 1400 m; 28 Jun. 2019; collection event: stn SC003; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0035 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°27.00′ N, 111°15.00′ E; depth 1550 m; 24 Mar. 2018; collection event: stn SC018; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ198775, MZ203271; IDSSE EEB-SW0021 • 2 specs; same collection data as for preceding; IDSSE EEB-SW0036, IDSSE EEB-SW0037 • 2 specs; South China Sea, SE of Hainan Island, seamount; 17°35.80′ N, 111°02.00′ E; depth 1750 m; 3 Apr. 2018; collection event: stn SC022; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0038, IDSSE EEB-SW0039 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°17.81′ N, 110°31.92′ E; depth 1460 m; 4 Apr. 2018; collection event: stn SC023; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB- SW0040 • 1 spec.; South China Sea, Xisha Islands, seamount; 17°06.00′ N, 110°58.20′ E; depth 1500 m; 23 Mar. 2018; collection event: stn SC017; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ198774, MZ203270; IDSSE EEB-SW0020 • 1 spec.; same collection data as for preceding; IDSSE EEB-SW0041. Description (IDSSE EEB-SW 0020) MEASUREMENTS. Disc diameter 13 mm, length of arms 80–100 mm. DiSC. Disc slightly pentagonal (Fig. 20A–B). Dorsal disc covered by thin, uncalcified, dark skin with surface of small projecting granules (Fig. 20A). Ventral disc smooth, with few or no smooth granules (Fig. 20B, E). Radial shields short, distally wider and widely separated (Fig. 21F). Distal half of radial shields uncovered, bearing few granules on outer margin but do not reach periphery of disc (Fig. 21F–G). Oral shields short, twice as wide as long and somewhat rhombic. Adoral shields short and wide, proximally meeting fully or some hardly meeting (Fig. 21A). Teeth significantly larger than oral papillae. Lateral oral papillae broad, flat, rounded, transparent, distal edges break easily (Fig. 21E). Number of lateral oral papillae varies among jaws, three per side, but some jaws have four oral papillae on one side (Fig. 21E). Genital slits conspicuous and extending from distal end of oral shield to periphery of disc (Fig. 21B). ARMS. Dorsal arm plate transversely oval with pointy corners, nearly twice as broad as long, covering only about half width of arm (Fig. 21C). First ventral arm plate transverse diamond-shaped, with rounded angles, next two plates square with convex outer margin. Beyond third ventral arm plate, arm segments nearly semicircular with slight peak, covering one third of width of arm segment (Fig. 21D–E). Tentacle scale absent on first arm segment and starts to appear from second or third arm segment (Fig. 21E). Lateral arm plates stout, forming well defined spine ridge and meeting on ventral side except on first two arm segments (Fig. 21D–F). Seven arm spines on an elevated ridge, four dorsal and three to four ventral. Dorsal arm spines often nearly two segments long, stout, nearly cylindrical and tapering to a blunt point (Fig. 21G). Ventral arm spines smaller, thorny with hook-shaped tip, with a few spiny points on their adoral or proximal side (Fig. 21H–I). Ventralmost arm spines on first few arm segments elongated and less hook-like, with rough surface but distalwards along arm developing into a short, little hyaline hook (Fig. 21I). COLOR. Dark olivaceous green on dorsal disc, light brown color on radial shield, dorsal arm spine, and dorsal and ventral arm plate; dark reddish brown on oral papillae and ventral arm spine (Fig. 20A–B). OSSiCLE MORPHOLOGY.Ventralmost arm spine short, thorny, with proximally oriented tip (Fig. 22A). Arm spine articulation well developed, with volute-shaped perforated lobe except in dorsal- and ventralmost articulations (Fig. 22B–C), with large muscle opening and small nerve opening (Fig. 22B–C). Vertebrae with short zygospondylous articulation with a broad dorsal extension of lateral muscle flanges, distally abruptly truncated, dorsal median furrow moderately expressed, and podial basins short and large (Fig. 22D–G). Middle segment of ventral vertebrae with deeply expressed furrow without oral bridge (Fig. 22F). Remarks The genus Ophientrema includes only two species, O. euphylactea (H.L. Clark, 1911) and O. scolopendrica (Lyman 1883). H.L. Clark (1911) mentioned a band of black spots on the dorsal disc of O. scolopendrica caused by tissue on the inner surface of the skin. In the present study, we examined nine specimens and all of them concurred with the description of the holotype of O. scolopendrica. However, there are some slightly different features in the color of the dorsal disc and number of lateral oral papillae, but the color of the present specimens matched the description by Koehler (1922a). Among the specimens from this study, we identified two different color patterns: 1) dark olivaceous green on the dorsal disc, light brown on radial shield, dorsal arm spine, and dorsal and ventral arm plate; 2) dark reddish brown on oral papillae and ventral arm spine, dark olivaceous green and brown on dorsal disc and bright red pink on radial shield, light brown on oral papillae, dorsal and ventral arm plate, and arm spine (Fig. 20A–D). Some specimens possessed seven oral papillae on one jaw, but when we examined our specimens and previous records, we considered this as intraspecific variation. Ophientrema euphylactea is distinguished from O. scolopendrica by the scale density on the dorsal disc and by having spiniform oral papillae (H.L. Clark 1911). Distribution 1000–2000 m depth. South China Sea, Eastern Japan, Indonesia (Gulf of Tomoni), Eastern China Sea, Tasman Sea, Madagascar (OBIS 2021). Genus Ophiurothamnus Matsumoto, 1917, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 39-44, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Lyman T. 1883. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Carribbean Sea (1878 - 79), and on the east coast of the United States, during the summer of 1880, by the U. S. coast survey steamer \" Blake \", commander J. R. Bartlett, U. S. Bulletin of the Museum of Comparative Zoology 10 (6): 227 - 287.","Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. United States National Museum Bulletin 75: 1 - 302.","Matsumoto H. 1917. A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo 38: 1 - 408.","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Ophiomoeris petalis sp. nov. urn:lsid:zoobank.org:act: 656A30A3-A81A-4A87-9C19-4007F194788A Figs 34–35 Diagnosis Disc with deep interradial incisions with seven lobes and ring of irregular scales bearing a few granules around centrodorsal plate and overlapping with radial shields. Seven thin arms curled under disc. Etymology The specific name is derived from the Latin word for flower petals, alluding to the shape of the disc. Material examined Holotype CHINA • South China Sea, SE of Zhongsha Islands, seamount; 13°58.65′ N, 114°52.09′ E; depth 1550 m; 25 Sep. 2020; collection event: stn SC013; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 203278; IDSSE EEB-SW0029. Paratypes CHINA • 5 specs; same collection data as for holotype; IDSSE EEB-SW0058 to EEB-SW0062. Description (holotype) MEASUREMENTS. Disc diameter 2.2 mm, heptamerous specimen. DiSC. Disc heptamerous with deep interradial incisions and a lobe above each arm, four large lobes, three smallest lobes and one intermediate lobe (signs of regeneration after fission). Arms differ in width in groups of 3, 3, 1 arms. Lobes formed by large drop-shaped radial shields, largest one a third of disc diameter in length and two to three times as long as wide (Fig. 34A–C). Radial shields distally connected, separated proximally by large triangular scales, covered by small conical granules (Fig. 34E). Center of disc sunken and covered by large, round centrodorsal plate without granules (Fig. 34A, C). Ring of irregular plates bearing a few conical granules around centrodorsal plate and overlapping with radial shields (Fig. 34A, C). Genital slits small, half as long as interradial ventral disc (Fig. 34F). Oral shields swollen, much smaller than adoral shields, as wide as long, fan-shaped with pointed proximal angle, slightly concave lateral edges and convex distal edge; size varies among radials (Fig. 34B, D, F). Adoral shields swollen, twice as wide as long, with angled, concave proximal edges of oral shield, not separating it from arm (Fig. 34F). Jaw as wide as long bearing one pointed ventralmost tooth and three spiniform lateral oral papillae, proximalmost one spine-like, other two shorter and rounded (Fig. 34F). All teeth spiniform like ventralmost tooth (Fig. 35B, D, F). ARMS. Seven thin arms, curled under disc. Dorsal arm plates fan-shaped, two times as wide as long, with convex distal edge and always separated (Fig. 34G). Ventral arm plate much wider than long on proximal segments, but reduced to small, round, thin scales, embedded in a strand of thick skin running along entire arm distally, always present along arm and always separated (Fig. 34H). Four thick, conical, smooth arm spines, two thirds arm segment in length (Fig. 34D, H). One minute tentacle scale clearly visible on proximal arm segments (Fig. 34D). COLOR. In alcohol, entire specimen creamy white. OSSiCLE MORPHOLOGY. Arm spine articulation formed by two thick, smooth, curved lobes, ventral lobe smaller than dorsal lobe, positioned at angle to distal edge of lateral plate, with large muscle opening and small nerve opening, the latter large in dorsalmost articulation. Volute-shape not well defined, absent in dorsalmost articulation, dorsal and ventral articular lobes connected but separating in ventral articulations (Fig. 35A–C). Vertebrae elongated, with streptospondylous articulation, dorsal and lateral furrows absent, middle section much lower than proximal part and distal muscle flanges, with straight ambulacral groove. Podial basins at distal end, tongue-like with round hole (Fig. 35D–F). Variations in paratypes Five heptamerous paratypes, with disc diameter ranging from 1.45 mm to 1.87 mm. All with similar morphological features as holotype, having conical granules on disc plates/scales and large, drop-shaped radial shields. Most paratypes with arms curled under disc. Remarks The oral frame arrangement and the lobe-like shape of the disc concur with the genus Ophiomoeris, which was recently transferred to Ophiacanthidae (O’Hara et al. 2018). The arm spine articulation of this genus is interpreted as a variation of the volute-shape typical of the family Ophiacanthidae. Previously only four species of Ophiomoeris were recognized and all of them are pentamerous: O. obstricta (Lyman, 1878), O. exuta Stöhr, 2011, O. nodosa (Koehler, 1905) and O. tenera (Koehler, 1897). The seven-fold symmetry is consistent in all our specimens. This is the first record of a sevenarmed (or indeed non-pentamerous) species in the genus Ophiomoeris, and this distinguishes it from all congeners. The size differences among the seven sections of the animals suggests that it is a fissiparous species. Morphological characters to differentiate species in the genus Ophiomoeris are otherwise difficult to interpret due to their high morphological variation among individuals. Taking geographic distribution into account, there may be several cryptic species complexes in the genus Ophiomoeris that can only be resolved by a molecular study (O’Hara & Stöhr 2006; Stöhr 2011). Distribution and habitat South China Sea (1550 m), found on a deep-sea seamount near the Zhongsha Islands. Order Amphilephidida O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017 Suborder Gnathophiurina Matsumoto, 1915 Superfamily Ophiactoidea Ljungman, 1867 Family Ophiactidae Matsumoto, 1915 Genus Ophiactis Lütken, 1856, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 61-64, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["O'Hara T. D., Stohr S., Hugall A. F., Thuy B. & Martynov A. 2018. Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification. European Journal of Taxonomy 416: 1 - 35. https: // doi. org / 10.5852 / ejt. 2018.416","Lyman T. 1878. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology 5 (7): 65 - 168.","Stohr S. 2011. New records and new species of Ophiuroidea (Echinodermata) from Lifou, Loyalty Islands, New Caledonia. Zootaxa 50 (1): 1 - 50. https: // doi. org / 10.11646 / zootaxa. 3089.1.1","Koehler R. 1905. Ophiures de l'expedition du Siboga. Part 2. Ophiures littorales. Siboga Expeditie 45 B: 1 - 140.","Koehler R. 1897. Echinodermes recueillis par \" l'Investigator \" dans l'Ocean Indien. I. Les ophiures de mer profonde. Annales des Sciences naturelles Zoologie 8 (4): 277 - 372.","O'Hara T. D. & Stohr S. 2006. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Richer de Forges B. & Justine J. - L. (ed.) Tropical Deep-Sea Benthos 24: 33 - 141. Museum national d'histoire naturelle, Paris.","O'Hara T. D., Hugall A. F., Thuy B., Stohr S. & Martynov A. V. 2017. Restructuring higher taxonomy using broad-scale phylogenomics: the living Ophiuroidea. Molecular Phylogenetics and Evolution 107: 415 - 430. https: // doi. org / 10.1016 / j. ympev. 2016.12.006","Matsumoto H. 1915. A new classification of the Ophiuroidea: with descriptions of new genera and species. Proceedings of the Academy of Natural Sciences of Philadelphia 67: 43 - 92."]}

Ophioplinthaca plicata (Lyman, 1878) Figs 25–26 Ophiomitra plicata Lyman, 1878: 150, pl. 8 figs 209–212, pl. 9 figs 233–235. Ophioplinthaca vicina Koehler, 1904: 129-130, pl. 25 figs 1–3. Ophiomitra plicata – Lyman 1882: 203–204, pl. 10 figs 7–9. — Li 1987: 143–145, pl. 1 fig. 2. — Liao 2004: 139–140, fig. 70. Ophioplinthaca plicata – O’Hara & Stöhr 2006: 84–85, fig. 8g, m–p. Material examined CHINA • 1 spec.; South China Sea, Zhongsha Islands, seamount; 15°36.20′ N, 113°33.74′ E; depth 1820 m; 27 Sep. 2019; collection event: stn SC014; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198773, MZ 203269; IDSSE EEB-SW0019. Remarks The present study found only one specimen of O. plicata , with 12.5 mm in disc diameter (Fig. 25). Within Chinese waters, this species has previously been recorded only from the South China Sea. The arm spine articulation is well developed and placed at a slight angle to the distal edge of the lateral arm plate. A volute-shaped perforated lobe is present in most articulations, but is reduced in the dorsalmost one (Fig. 26A–B). The arm spine articulation has a large muscle opening and a small nerve opening (Fig. 26A–B), and it decreases significantly in size ventralwards (Fig. 26A). The vertebrae have a streptospondylous articulation, with a short, broad podial basin at the proximal end and a narrow, small distal end. The dorsal end of the vertebrae is distally triangular and proximally flattened with a longitudinal groove along the midline (Fig. 26C–G). The ventral end of the vertebrae has a broad ambulacral groove without an oral bridge (Fig. 26E). The genus Ophioplinthaca is clearly distinguishable from other genera within the family Ophiacanthidae by the deep interradial incisions into the disc, which are lined distally by enlarged disc scales. Ophioplinthaca plicata is morphologically variable among individuals and is difficult to distinguish from other species of Ophioplinthaca, especially from O. pulchra Koehler, 1904. The morphological features of the specimen of O. plicata from our collection and previous descriptions show complex morphological variation among individuals, and more specimens need to be analyzed from neighboring seas and the Indo-Pacific region to understand their morphological variation with respect to geographic distribution (O’Hara & Stöhr 2006). A molecular analysis using specimens from many localities is required to understand the genetic variation in this species and its impact on morphological variation. Distribution 480–2003 m depth. South China Sea, Philippines, Indonesia, New Caledonia, Kermadec Island, New Zealand, SE Australia (O’Hara & Stöhr 2006; OBIS 2021). Genus Ophiacantha Müller & Troschel, 1842, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on page 47, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Lyman T. 1878. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology 5 (7): 65 - 168.","Koehler R. 1904. Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. Siboga Expeditie 45 A: 1 - 176.","Lyman T. 1882. Report on the Ophiuroidea. Report of the Scientific Results of the Voyage of H. M. S. Challenger 1873 - 76, Zoology 5 (1): 1 - 386.","Li G. 1987. Deep-sea ophiurans in the South China Sea. Nanhai Studia Marina Sinica 8: 143 - 153.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","O'Hara T. D. & Stohr S. 2006. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Richer de Forges B. & Justine J. - L. (ed.) Tropical Deep-Sea Benthos 24: 33 - 141. Museum national d'histoire naturelle, Paris.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021].","Muller J. & Troschel F. H. 1842. System der Asteriden. 1. Asteriae. 2. Ophiuridae. Vieweg, Braunschweig, Germany."]}