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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."]}