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

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

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

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

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

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

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

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

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

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

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

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

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

Brittle stars (class Ophiuroidea) are marine invertebrates comprising approximately 2, 100 extant species, and are considered to constitute the most diverse taxon of the phylum Echinodermata. As a non-invasive method for monitoring biodiversity, we developed two new sets of PCR primers for metabarcoding environmental DNA (eDNA) from brittle stars. The new primer sets were designed to amplify 2 short regions of the mitochondrial 16S rRNA gene, comprising a conserved region (111–115 bp, 112 bp on average; named “16SOph1”) and a hyper-variable region (180–195 bp, 185 bp on average; named “16SOph2”) displaying interspecific variation. The performance of the primers was tested using eDNA obtained from two sources: a) rearing water of an 2.5 or 170 L aquarium tanks containing 15 brittle star species and b) from natural seawater collected around Misaki, the Pacific coast of central Japan, at depths ranging from shallow (2 m) to deep (> 200 m) sea. To build a reference library, we obtained 16S rRNA sequences of brittle star specimens collected from around Misaki and from similar depths in Japan, and sequences registered in International Nucleotide Sequence Database Collaboration. As a result of comparison of the obtained eDNA sequences with the reference library 37 (including cryptic species) and 26 brittle star species were detected with certain identities by 16SOph1 and 16SOph2 analyses, respectively. In shallow water, the number of species and reads other than the brittle stars detected with 16SOph1 was less than 10% of the total number. On the other hand, the number of brittle star species and reads detected with 16SOph2 was less than half of the total number, and the number of detected non-brittle star metazoan species ranged from 20 to 46 species across 6 to 8 phyla (only the reads at the “Tank” were less than 0.001%). The number of non-brittle star species and reads at 80 m was less than 10% with both of the primer sets. These findings suggest that 16SOph1 is specific to the brittle star and 16SOph2 is suitable for a variety of marine metazoans. It appears, however, that further optimization of primer sequences would still be necessary to avoid possible PCR dropouts from eDNA extracts. Moreover, a detailed elucidation of the brittle star fauna in the examined area, and the accurate identification of brittle star species in the current DNA databank is required., 汲んだ水から深海生物の種類を判別 --世界初「クモヒトデメタバーコーティング」技術を開発--. 京都大学プレスリリース.

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

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

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

This Zenodo upload contains data from the draft genome of the brittle star Ophioderma brevispinum (Say, 1859). Please read our READ-ME.mdfile for additional details. You can citethe paper: Mashanov, V., Machado, D.J., Reid, R.et al.Twinkle twinkle brittle star: the draft genome ofOphioderma brevispinum(Echinodermata: Ophiuroidea) as a resource for regeneration research.BMC Genomics23, 574 (2022). https://doi.org/10.1186/s12864-022-08750-y. Abstract: Background—Echinoderms are established models in experimental and developmental biology, however genomic resources are still lacking for many species. Here, we present the draft genome ofOphioderma brevispinum, an emerging model organism in the field of regenerative biology. This new genomic resource provides a reference for experimental studies of regenerative mechanisms. Results—We report a de novo nuclear genome assembly for the brittle starO. brevispinumand annotation facilitated by the transcriptome assembly. The final assembly is 2.68 Gb in length and contains 146,703 predicted protein-coding gene models. We also report a mitochondrial genome for this species, which is 15,831 bp in length, and contains 13 protein-coding, 22 tRNAs, and 2 rRNAs genes, respectively. In addition, 29 genes of the Notch signaling pathway are identified to illustrate the practical utility of the assembly for studies of regeneration. Conclusions—The sequenced and annotated genome ofO. brevispinumpresented here provides the first such resource for an ophiuroid model species. Considering the remarkable regenerative capacity of this species, this genome will be an essential resource in future research efforts on molecular mechanisms regulating regeneration. &nbsp

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

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

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

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

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

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

Ophiurothamnus clausa (Lyman, 1878) Figs 23–24 Ophioceramis clausa Lyman, 1878: 124, pl. 6 figs 161–163. Ophiothamnus stultus Koehler, 1904: 141–142, pl. 25 figs 9–10, pl. 26 fig. 1. Ophiurothamnus musorstomae Guille, 1981: 427, fig. 1g –j, pl. 3 figs 20–21. Ophioceramis clausa – Lyman 1882: 26, pl. 11 figs 4–6. Ophiurothamnus stultus – Matsumoto 1917: 130. — Koehler 1922a: 104–105, pl. 22 fig. 1–4. — Liao 2004: 149, fig. 78. Ophiurothamnus clausa – O’Hara & Stöhr 2006: 105, fig. 14 (a–j). — Chen et al. 2020: 651–652, figs 1–2. Material examined CHINA • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°17.60′ N, 111°34.17′ E; depth 1500 m; 2 Apr. 2018; collection event: stn SC021; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198777; IDSSE EEB-SW0023 • 2 specs; South China Sea, SE of Hainan Island, seamount; 17°59.21′ N, 111°01.17′ E; depth 1500 m; 1 Apr. 2018; collection event: stn SC020; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0042, IDSSE EEB-SW0043. Remarks The disc diameter (4.5–5.0 mm), the circular disc and the morphology are similar to the description of Ophiurothamnus clausa in O’Hara & Stöhr (2006) and to the description from the South China Sea in Chen et al. (2020), but we identified some variability in the number of scales on the dorsal disc and in the shape of the radial shields (Fig. 23). The arm skeleton characters of O. clausa differ from those of other species in the family Ophiacanthidae. The dorsal arm plate is triangular and well developed (Fig. 24A). The arm spine articulation is well developed and has a large muscle opening and a small nerve opening. A volute-shaped perforated lobe is present in most articulations, but is lacking in the dorsalmost one (Fig. 24B). A perforation is present on the inner side of each lateral arm plate (Fig. 24C). The vertebrae have a long streptospondylous articulation, with broad proximal and distal ends and a narrow middle segment. The proximal end of a vertebra has two clearly separated openings and the distal end of the podial basin becomes short and small. The dorsal side of the vertebrae is distally triangular and proximally flattened, without a keel. The ventral side of the vertebrae has a narrow and straight ambulacral furrow without an oral bridge (Fig. 24D–G). Ophiurothamnus clausa has variable morphological features according to O’Hara & Stöhr (2006), especially regarding the characters of the disc, and the variation in disc covering is very striking, ranging from smooth naked plates to plates with granules, the number and shape of the scales covering the disc, the shape and position of the radial shields and the shape of the arm spines. These character differences cannot be explained by biogeographic distribution or size of the animal (O’Hara & Stöhr 2006) and may instead be evidence of cryptic speciation. Distribution 480–3202 m depth. East China Sea, South China Sea, Indonesia, Australia, New Zealand, Kermadec Islands, Philippines, New Caledonia, Papua New Guinea, Mozambique Channel (O’Hara & Stöhr 2006; OBIS 2021). Genus Ophioplinthaca Verrill, 1899, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 44-47, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Lyman T. 1878. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology 5 (7): 65 - 168.","Koehler R. 1904. Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. Siboga Expeditie 45 A: 1 - 176.","Guille A. 1981. Echinodermes: Ophiurides. In: Forest J. (ed.) Resultats des Campagnes MUSORSTOM: 1. Philippines. Memoires ORSTOM 91: 413 - 456. Museum national d'histoire naturelle, Paris.","Lyman T. 1882. Report on the Ophiuroidea. Report of the Scientific Results of the Voyage of H. M. S. Challenger 1873 - 76, Zoology 5 (1): 1 - 386.","Matsumoto H. 1917. A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo 38: 1 - 408.","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","O'Hara T. D. & Stohr S. 2006. Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Richer de Forges B. & Justine J. - L. (ed.) Tropical Deep-Sea Benthos 24: 33 - 141. Museum national d'histoire naturelle, Paris.","Chen W. Y., Zhang D. & Wang C. 2020. Two new records of genus Ophiurothamnus (Ophiuroidea, Ophiacanthidae) from a deep-sea seamount of the South China Sea. Oceanologia et Limnologia Sinica 51 (3): 649 - 655. https: // doi. org / 10.11693 / hyhz 20191100232","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Ophiacantha bathybia H.L. Clark, 1911 Figs 27–28 Ophiacantha bathybia H.L. Clark, 1911: 233–234. Material examined CHINA • 1 spec.; South China Sea, E of Hainan Island, seamount; 18°11.96′ N, 114°21.01′ E; depth 3536 m; 11 Sep. 2017; collection event: stn SC016; MSV Shenhaiyongshi leg.; GenBank: MZ 203273; IDSSE EEB-SW0024 • 1spec.; South China Sea,E of Hainan Island, seamount; 18°11.93′N, 114°21.01′ E; depth 1550 m; 9 Sep. 2017; collection event: stn SC016; MSV Shenhaiyongshi leg.; GenBank: MZ 203274; IDSSE EEB-SW0025 • 1 spec.; South China Sea, E of Hainan Island; 18°12.03′ N, 114°21.25′ E; depth 3500 m; 6 Sep. 2017; collection event: stn SC016; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW 0044. Description (IDSSE EEB-SW 0025) MEASUREMENTS. Disc diameter 17.5 mm. DiSC. Flat, pentagonal, covered by thin skin, underlying scales with short disc spines (Fig. 27A–B), 0.3–0.4 mm high, rough, with two to three sharp terminal thorns, similar on both dorsal and ventral disc (Fig. 27C–E). Radial shields long, narrow, well separated, parallel to each other, concealed by thin skin, their form and position clearly visible through skin, with thorny stumps (Fig. 27A, E). Ventral disc near oral shields with scales without thorny stumps (Fig. 27B). Oral shield much wider than long, broadly triangular, with wide, pointed proximal angle and a straight or convex distal edge (Fig. 27F). Madreporite larger, with central depression, pentagonal. Adoral shields large, three times as long as wide, narrow, not separated (Fig. 27B, F). Adoral shields enclose proximal oral shield edges and extend around it, separating it from first lateral arm plate (Fig. 27C, F). Jaws wider than long, ventralmost tooth with large, blunt, pointed or flat edge, and three pointed, spiniform lateral oral papillae with thick and rounded base (Fig. 27F). Genital slits conspicuous and extending from oral shield to periphery of disc (Fig. 27I). ARMS. Dorsal arm plate on first few arm segments triangular, somewhat fan-shaped and distal margin more convex, but along arm becoming straighter, towards rhombic, somewhat swollen, two times as wide as long, barely separated (Fig. 27G). Ventral arm plate widely triangular, two times as wide as long, distal margin convex, proximally with low, wide angle, lateral side weakly concave and widely separated, but along arm ventral arm plate decreasing in size, as wide as long, with convex distal margin (Fig. 27H). Lateral arm plates meeting above and below, but along arm becoming separated ventrally (Fig. 27H). Six sharp and thorny arm spines (Fig. 27J). Three uppermost spines longest, two to three arm segments in length, one to two dorsal arm spines smooth but others thorny (Fig. 27K). Two to three tapering ventral arm spines with rough tip (Fig. 24L). One tentacle scale, elongated, half as long as ventral arm plate, pointed (Fig. 27I). COLOR. When alive, entire specimen light red, light brown when dry (Fig. 27A–B). OSSiCLE MORPHOLOGY. Arm spine articulation well developed and placed at small angle to distal edge of lateral arm plate (Fig. 28A–B). Volute-shaped perforated lobe forms most articulations, but reduced in dorsalmost articulation (Fig. 28A–B). Arm spine articulation with large muscle opening (Fig. 28B). Ventral arm spine smooth, but with rough tip (Fig. 28C). Vertebrae with a well-developed zygospondylous articulation, with a broad dorsal surface, distally abruptly truncated, with a shallow dorsal medial furrow, podial basins slightly wider than long (Fig. 28D–H). Ambulacral groove widened in middle, without oral bridge (Fig. 28G). Remarks Ophiacantha bathybia was described by H.L. Clark (1911); additional specimens have been collected in 1980, 1981 and 2015 (OBIS 2021). Ophiacantha bathybia from the present study is quite similar to the holotype description, but it differs in the arm spine and arm plate characters. Our specimens were larger than the holotype (12 mm disc diameter) and some of the morphological differences may be caused by this size difference. The lateral arm plates in the holotype description are connected at both the dorsal and ventral edges, but in our specimens they were only connected by a ligament. Another morphological variation was the number of thorny spines, which differs from segment to segment and arm to arm. Ophiacantha bathybia has no uniquely distinguishing characters, but appears to be different from other species of Ophiacantha by the size of the disc and characters of the disc covering, dorsal arm plates, arm spines and tentacle scale. Mature specimens have narrow, long radial shields and thorny disc stumps, but differ in arm spine and dorsal arm plate shape. It has been recorded from abyssal depths, and its morphological characters are similar to those of other abyssal species of Ophiacantha, namely O. pacifica Lütken & Mortensen, 1899, O. sollicita Koehler, 1922, O. cosmica Lyman, 1878, O. frigida Koehler, 1907 and O. sociabilis Koehler, 1897, but these species have been recorded from Panama, the Southern Ocean and the Atlantic Ocean. Ophiacantha bathybia may be considered as a sister species to these abyssal species of Ophiacantha based on their morphological features. Ophiacantha cosmica differs from O. bathybia by having up to eight arm spines, slender lateral oral papillae without a thick base and a blunt ventralmost tooth (Lütken & Mortensen 1889; Stöhr & O’Hara 2021). Ophiacantha sociabilis differs from O. bathybia by having four to five lateral oral papillae, a less enlarged distalmost papilla and wider jaws (Koehler 1897; Stöhr & O’Hara 2021). Ophiacantha sollicita differs from O. bathybia by having up to eight arm spines, conical disc spines, a notably thickened distal oral papilla and non-moniliform arms (Koehler 1922b). Ophiacantha frigida differs from O. bathybia by having a larger distalmost lateral oral papilla and usually two tentacle scales on the first tentacle pore (Koehler 1922b). Ophiacantha pacifica is highly similar to O. bathybia in morphological features of the oral frame, as well as the number and length of arm spines, but the ventralmost arm spines of O. bathybia have a rough tip (Lütken & Mortensen 1889) (Fig. 28C). However, these morphological differences vary and overlap among individuals between species of the genus Ophiacantha. Therefore, a molecular analysis from a wider range of localities is needed to understand the species boundaries. Distribution 1602–3656 m depth. South China Sea, Alaska, British Colombia, Bering Sea, Shumagin Island, Makassar Strait and Northwest Pacific (OBIS 2021)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 47-53, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. United States National Museum Bulletin 75: 1 - 302.","Lyman T. 1878. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology 5 (7): 65 - 168.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021].","Koehler R. 1907. Note preliminaire sur quelques asteries et ophiures provenant des campagnes de la Princesse Alice. Bulletin de l'Institut oceanographique 99: 1 - 47.","Koehler R. 1897. Echinodermes recueillis par \" l'Investigator \" dans l'Ocean Indien. I. Les ophiures de mer profonde. Annales des Sciences naturelles Zoologie 8 (4): 277 - 372.","Lutken C. F. & Mortensen T. 1889. Reports on an exploration off the west coasts of Mexico, Central and Southern America and off the Galapagos Islands. XXV. The Ophiuridae. Memoirs of the Museum of Comparative Zoology 23 (2): 97 - 208.","Koehler R. 1922 b. Echinodermata: Ophiuroidea. Australasian Antarctic Expedition 1911 - 1914, Scientific Report Series C 8 (2): 5 - 98."]}

Gorgonocephalus cf. dolichodactylus Döderlein, 1911 Figs 11–12 Gorgonocephalus dolichodactylus Döderlein, 1911: 34–36, pl. 1 figs 4–5, pl. 7 figs 3, 4a–b. Gorgonocephalus dolichodactylus – Döderlein 1927: 27, 52. — Matsumoto 1915: 73, fig. 20. — Baker 1980: 52, figs 18a, 20, 30. — Liao & Clark 1995: 171, fig. 75. — McKnight 2000: 45–46, pl. 20. Material examined CHINA • 1 spec.; South China Sea, Zhongsha Islands, seamount; 13°36.00′ N, 114°34.49′ E; depth 1340 m; 30 Mar. 2020; collection event: stn SC008; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198760; IDSSE EEB-SW0006. Remarks The disc diameter was 67 mm. Our specimen is similar to the holotype description by Döderlein (1911) and the description in Liao & Clark (1995), but showed some morphological variations, especially on the disc (Fig. 11). Therefore, we hesitate to fully associate our specimen with G. dolichodactylus. The original description and the description in Liao & Clark (1995) mention small granules on both the dorsal and ventral disc, but the present specimen is completely naked except for the radial shields (Fig. 11A–E), which are covered by scattered granules (Fig. 11F). Pedicellarial bands are formed by approximately 12 articulating tubercles at the curved distal end of the baseplate (Fig. 12B), and these articulations have a single foramen (Fig. 12C). The distal end of the baseplate internal side becomes curved with perforations on the ventral side of the baseplate (Fig. 12B–C). The vertebrae have a streptospondylous articulation with smooth lateral furrows and no oral bridge (Fig. 12D–H). The external side of the lateral arm plate has three separate tubercle-shaped articulations with a single opening and one large muscle opening at the edge. Gorgonocephalus dolichodactylus was first recorded from the South China Sea in southeastern Hainan, at a depth of 1100 m, in 1959. Distribution 146–1357 m depth. South China Sea, Japan, Korea, Philippines, Australia and New Zealand (Liao 2004; OBIS 2021). Order Ophiurida Müller & Troschel, 1840 sensu O’Hara et al. 2017 Suborder Ophiomusina O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017 Family Ophiomusaidae O’Hara, Stöhr, Hugall, Thuy & Martynov, 2018 Genus Ophiomusa Hertz, 1927, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 25-28, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Doderlein L. 1911. Uber japanische und andere Euryalae. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse Suppl. 5 (2): 1 - 123.","Doderlein L. 1927. Indopacifische Euryalae. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse 31 (6): 1 - 106.","Matsumoto H. 1915. A new classification of the Ophiuroidea: with descriptions of new genera and species. Proceedings of the Academy of Natural Sciences of Philadelphia 67: 43 - 92.","Baker A. N. 1980. Euryalinid Ophiuroidea (Echinodermata) from Australia, New Zealand, and the South-west Pacific Ocean. New Zealand Journal of Zoology 7 (1): 11 - 83. https: // doi. org / 10.1080 / 03014223.1980.10423763","Liao Y. & Clark A. M. 1995. The Echinoderms of Southern China. Science Press, Beijing.","McKnight D. G. 2000. The marine fauna of New Zealand: basket-stars and snake-stars (Echinodermata: Ophiuroidea: Euryalinida). NIWA Biodiversity Memoir 115: 1 - 79.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021].","O'Hara T. D., Hugall A. F., Thuy B., Stohr S. & Martynov A. V. 2017. Restructuring higher taxonomy using broad-scale phylogenomics: the living Ophiuroidea. Molecular Phylogenetics and Evolution 107: 415 - 430. https: // doi. org / 10.1016 / j. ympev. 2016.12.006","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","Hertz M. 1927. Die Ophiuroiden der Deutschen Tiefsee-Expedition. I. Chilophiurida Matsumoto (Ophiolepididae, Ophioleucidae, Ophiodermatidae, Ophiocomidae). Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer Valdivia, 1898 - 1899 22 (3): 59 - 122."]}

Ophiomusa sp. Fig. 13H–L Material examined CHINA • 1 spec.; South China Sea, near Xisha Islands; 16°39.75′ N, 112°7.43′ E; depth 663 m; 15 Mar. 2020; collection event: stn SC006; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198764; IDSSE EEB-SW0010. Remarks We collected a damaged specimen that could only be identified to genus level as Ophiomusa. It differs from O. lymani by the coverage of irregular scales on the disc center, the radial shields being smaller and more triangular, large ventral disc scales connected to the oral shield entirely covering the interradial space between the genital plates and having an ventral arm plate present on up to seven arm segments from the arm base (Fig. 13H–L). Ophiomusa sp. forms a sister clade to O. lymani on our molecular tree (see below). In the phylogeny by Christodoulou et al. (2019), this sister clade is composed of O. faceta (Koehler, 1922a) and O. facunda (Koehler, 1922a), which suggests that our specimen may also belong to one of these species. Ophiomusa faceta is similar to Ophiomusa sp. by having irregular disc scales on the disc center and radial shields separated by a single layer of disc scales, but differs by lacking a ventral arm plate beyond the second arm segment, smooth dorsal disc surface and 6–7 arm spines on the lateral arm plate. Ophiomusa facunda is similar to Ophiomusa sp. by having a rough dorsal disc surface and radial shields separated by a single layer of disc scales, but differs in having large dorsal disc scales, the entire ventral surface occupied by a large interradial scale, in lacking a ventral arm plate beyond the third arm segment and having 6–7 arm spines on the lateral arm plate. The differences between those species and our specimen prevent us from associating it with either of them. Superorder Ophintegrida O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017 Order Ophiacanthida O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017 Suborder Ophiacanthina O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017 Family Ophiotomidae Paterson, 1985 Genus Ophiotreta Verrill, 1899, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 28-31, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Christodoulou M., O'Hara T. D., Hugall A. F. & Arbizu P. M. 2019. Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology 29 (22): 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","Thomson C. W. 1873. The Depths of the Sea. Macmillan and Co., London. Thuy B. & Stohr S. 2016. A new morphological phylogeny of the Ophiuroidea (Echinodermata) accords with molecular evidence and renders microfossils accessible for cladistics. PLoS One 11 (5): e 156140. https: // doi. org / 10.1371 / journal. pone. 0156140","O'Hara T. D., Hugall A. F., Thuy B., Stohr S. & Martynov A. V. 2017. Restructuring higher taxonomy using broad-scale phylogenomics: the living Ophiuroidea. Molecular Phylogenetics and Evolution 107: 415 - 430. https: // doi. org / 10.1016 / j. ympev. 2016.12.006","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."]}

Ophiactis profundi Lütken & Mortensen, 1889 Figs 38–39 Ophiactis profundi Lütken & Mortensen, 1889: 140–142, pl. 6 figs 4–6. Ophiactis pteropoma H.L. Clark, 1911: 134, fig. 50. Ophiactis pteropoma – H.L. Clark 1915: 264. — Matsumoto 1917: 154. Ophiactis profundi – Koehler 1922a: 192, pl. 63 fig. 8. — Guille 1981: 439. — Liao 2004: 235–236, fig. 139. Material examined CHINA • 1 spec.; South China Sea, SE of Zhongsha Islands, seamount; 13°58.65′ N, 114°52.09′ E; depth 1550 m; 25 Sep. 2020; collection event: stn SC013; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198771; IDSSE EEB-SW0017 • 1 spec.; same collection data as for preceding; GenBank: MZ 198772; IDSSE EEB-SW0018 • 5 specs; same collection data as for preceding; IDSSE EEB-SW0064 to EEB-SW0068. Remarks Ophiactis profundi is a hexamerous, fissiparous species. The disc diameter ranged from 4 mm to 6 mm and all the specimens were found at one station on a deep-sea seamount in the South China Sea. Morphological descriptions of the holotype of Ophiactis profundi (Lütken & Mortensen 1889) from the eastern Pacific Ocean and of other specimens from the Philippine Sea (Koehler 1922a) were similar to our specimens (Fig. 38). The dorsal arm plates are well-developed, widely triangular (Fig. 39A). The lateral arm plate has three well-developed arm spine articulations, formed by two subparallel bent lobes, not connected to each other, placed at an angle to the distal edge and equal in size, with two similar openings for muscle and nerve (Fig. 39B–C). The vertebrae have a well-developed zygospondylous articulation, with a narrow, shallow dorsal furrow, not extending beyond the distal articulation, and the ambulacral groove is distalwards widened (Fig. 39D–F). Ophiactis profundi is closely related to Ophiactis flexuosa Lyman, 1879, but it differs in the shape of the oral shield and ventral arm plate, the shape of the oral papillae and the number of arms (O. flexuosa is pentamerous). Ophiactis flexuosa has distinct scales all around the radial shields (Lütken & Mortensen 1889). Ophiactis plana Lyman, 1869 is related to O. profundi, but it differs in the shape of the adoral shields and oral shield, and in the smaller oral papillae. Distribution 231–1644 m. From the South China Sea recorded from the Lubang Islands near the Philippines (this part of the South China Sea is sometimes called the West Philippine Sea), East China Sea, Bohol Sea, Gulf of Tomini, Bismarck Sea, Coral Sea, Australia and New Zealand (OBIS 2021)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on page 68, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Lutken C. F. & Mortensen T. 1889. Reports on an exploration off the west coasts of Mexico, Central and Southern America and off the Galapagos Islands. XXV. The Ophiuridae. Memoirs of the Museum of Comparative Zoology 23 (2): 97 - 208.","Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. United States National Museum Bulletin 75: 1 - 302.","Clark H. L. 1915. Catalogue of recent ophiurans, based on the collection of the Museum of Comparative Zoology. Memoirs of the Museum of Comparative Zoology at Harvard College 25 (4): 164 - 376.","Matsumoto H. 1917. A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo 38: 1 - 408.","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","Guille A. 1981. Echinodermes: Ophiurides. In: Forest J. (ed.) Resultats des Campagnes MUSORSTOM: 1. Philippines. Memoires ORSTOM 91: 413 - 456. Museum national d'histoire naturelle, Paris.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","Lyman T. 1879. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part II. Bulletin of the Museum of Comparative Zoology 6 (2): 17 - 83.","Lyman T. 1869. Preliminary report on the Ophiuridae and Astrophytidae dredged in deep water between Cuba and Florida Reef. Bulletin of the Museum of Comparative Zoology 1: 309 - 354.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Asteronyx loveni Müller & Troschel, 1842 Figs 2–3 Asteronyx loveni Müller & Troschel, 1842: 119–120, pl. 10 figs 3–5. Ophiuropsis lymani Studer, 1884: 55–46, pl. 5 fig. 12a–d. Asteronyx dispar Lütken & Mortensen, 1889: 185, pls 21–22. Asteronyx locardi Koehler, 1895: 470–471, fig. 10. Asteronyx cooperi Bell, 1909: 22. Ophiuraster patersoni Litvinova, 1998: 441–444, fig. 3. Asteronyx loveni – Döderlein 1927: 59, 97, pl. 7 figs 7–8. — Baker 1980: 12, 16–18, figs 2–3. — Liao & Clark 1995: 165–166, fig. 71. — McKnight 2000: 8, 13–15, pl. 1. — Olbers et al. 2019: 49–50, fig. 23. Ophiuraster patersoni – Stöhr 2005: 545–546, fig. 1. Material examined CHINA • 1 spec.; South China Sea, SE of Hainan Island, seamount; 18°31.76′ N, 112°40.56′ E; depth 1167 m; 27 Jun. 2019; collection event: stn SC002; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198756, MZ 203264; IDSSE EEB-SW0002. Remarks Disc diameter 11 mm and collected attached to a gorgonian species. Our specimen is similar to the holotype description by Müller & Troschel (1842) and later published descriptions (Baker 1980; McKnight 2000; Olbers et al. 2019) (Fig. 2). Vertebrae with a streptospondylous articulation and the lateral arm plate bears four to five spine articulations, which lack a separate nerve opening (Fig. 3). Species of Asteronyx are usually found on mud and sand, associated with gorgonians and pennatulids. In 1959 and from 1976 to 1981, 52 specimens of A. loveni were collected from the East and South China seas, at depths of 510–1100 m. Asteronyx loveni was first reported from the South China Sea by Chang et al. (1962). Distribution 62–4721 m depth. Global, except Arctic and Antarctic (Olbers et al. 2019; OBIS 2021)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 11-12, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Muller J. & Troschel F. H. 1842. System der Asteriden. 1. Asteriae. 2. Ophiuridae. Vieweg, Braunschweig, Germany.","Studer T. 1884. Verzeichnis der wahrend der Reise S. M. S. ' Gazelle' um die Erde, 1874 - 76 gesammelten Asteriden und Euryaliden. Abhandlungen der preussischen Akademie der Wissenschaften 2: 1 - 64.","Lutken C. F. & Mortensen T. 1889. Reports on an exploration off the west coasts of Mexico, Central and Southern America and off the Galapagos Islands. XXV. The Ophiuridae. Memoirs of the Museum of Comparative Zoology 23 (2): 97 - 208.","Koehler R. 1895. Dragages profonds executes a bord du Caudan dans le Golfe de Gascogne. Rapport preliminaire sur le echinodermes. Revue biologique du Nord de la France 7: 439 - 49.","Bell F. J. 1909. Report on the Echinoderma (other than holothurians) collected by Mr. J. Stanley Gardiner in the western parts of the Indian Ocean. Transactions of the Linnean Society of London, Series 2 2: 17 - 22. Available from https: // www. biodiversitylibrary. org / page / 16398922 [accessed 16 Feb. 2022].","Litvinova N. M. 1998. Two new species of the genus Ophiuraster (Ophiurinae, Ophiuroidea, Echinodermata) from French collections and some remarks on the genus. Zoosystema 20 (3): 439 - 444.","Doderlein L. 1927. Indopacifische Euryalae. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse 31 (6): 1 - 106.","Baker A. N. 1980. Euryalinid Ophiuroidea (Echinodermata) from Australia, New Zealand, and the South-west Pacific Ocean. New Zealand Journal of Zoology 7 (1): 11 - 83. https: // doi. org / 10.1080 / 03014223.1980.10423763","Liao Y. & Clark A. M. 1995. The Echinoderms of Southern China. Science Press, Beijing.","McKnight D. G. 2000. The marine fauna of New Zealand: basket-stars and snake-stars (Echinodermata: Ophiuroidea: Euryalinida). NIWA Biodiversity Memoir 115: 1 - 79.","Olbers J. M., Griffiths C. L., O'Hara T. D. & Samyn Y. 2019. Field guide to the brittle and basket stars (Echinodermata: Ophiuroidea) of South Africa. Abc Taxa 19: 1 - 354. Available from http: // www. abctaxa. be / volumes / volume _ 19 _ fieldguide-brittle-and-basket-stars [accessed 16 Feb. 2022].","Stohr S. 2005. Who's who among baby brittle stars (Echinodermata: Ophiuroidea): postmetamorphic development of some North Atlantic forms. Zoological Journal of the Linnean Society 143 (4): 543 - 576. https: // doi. org / 10.1111 / j. 1096 - 3642.2005.00155. x","Chang F. Y., Liao Y. L. & Wu B. L. 1962. Euryaliae of the China Sea. Acta Zoologica Sinica 14: 53 - 68.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Gorgonocephalus chilensis novaezelandiae Mortensen, 1924 Figs 9–10 Gorgonocephalus chilensis var. novaezelandiae Mortensen, 1924: 109–110, pl. 4 fig 1. Gorgonocephalus chilensis – Baker 1980: 51–52. — McKnight 2000: 45–46, pl. 19. [non G. chilensis chilensis Philippi, 1858] Material examined CHINA • 1 spec.; South China Sea, SE of Zhongsha Islands, seamount; 13° 58.68′ N, 114° 52.09′ E; depth 1550 m; 25 Sep. 2020; collection event: stn SC013; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198761; IDSSE EEB-SW0007. Description (IDSSE EEB-SW 0007) MEASUREMENTS. Disc diameter 15.5 mm. DiSC. Dorsal disc slightly inflated, interradials slightly indented. Radial shields elongated and narrow, extending nearly toward center of disc but not meeting in center, tapering at distal ends, densely covered by large, tall conical granules. Skin between radial shields also covered by conical granules, but less dense and smaller than on radial shields, but disc center covered with compacted conical granules. Disc periphery covered with few larger conical granules (Fig. 9A–F). Ventral disc covered with small, scattered, low granules, extending onto oral area (Fig. 9E). Genital slits conspicuous, interradial margin covered by two irregular rows of larger, higher than wide granules (Fig. 9D). Single madreporite. Oral area covered by smooth skin, partly exposing adoral shield outlines and few scattered smaller granules (Fig. 9E). Adoral shields short, square. Oral papillae spiniform (Fig. 9E). ARMS. Branched at least six to seven times, flexible dorso-ventrally, flat ventrally, high rounded dorsally (Fig. 9A). Ventral arm along first branch and near base covered by smooth skin, distalwards scattered with smaller granules (Fig. 9G). Dorsal arm surface covered by domed scales, on proximal segments with naked scales and naked areas corresponding to pedicellarial bands. Dorsal arm surface densely covered by compact granules after second arm fork. Pedicellarial bands start at second arm fork with three to four isolated clumps on each side of arm and becoming continuous across arm. From sixth arm fork, raised pedicellarial bands give an annulated appearance to arm (Fig 9H). First arm segment lacks spines, next three with two arm spines, next nine to ten with three arm spines and thereafter four arm spines per segment, decreasing to three after fifth branch (Fig. 9G, I–J). Ventral arm spines smaller, slightly flattened, unevenly pointed, distally turning into multi-toothed hooks (Fig. 9J–L). Pedicellariae with small secondary tooth (Fig. 9K–L). COLOR. Creamy white in alcohol specimen, with light brown disc and darker arms when alive (Fig. 9A–B). OSSiCLE MORPHOLOGY. Pedicellarial band formed by approximately six articulating tubercles on middle arm region and eight articulations at curved distal end (Fig. 10A–B). Tubercles form two parallel rows with single foramen (Fig. 10A–B). Ventral arm spines distally transformed into hooks with two or three secondary teeth (Fig. 10C). Pedicellariae on pedicellarial band with single secondary tooth and apophysis (Fig. 10D). Pedicellariae on pedicellarial band differ from ventral arm spine by smooth apophysis. Vertebrae with hourglass-shaped streptospondylous articulation with smooth lateral furrows (Fig. 10E–I). Paired openings in lateral side of vertebrae for lateral water canals, no oral bridge (Fig. 10F–G). Remarks The subspecies G. chilensis novaezelandiae is currently unaccepted and considered a junior synonym of G. chilensis (Philippi, 1858) (Stöhr et al. 2021). Our molecular results (see below) place this specimen with other New Zealand material in a sister clade to G. chilensis from Antarctica and the Southern Ocean. We consider the New Zealand clade sufficiently different from the Antarctic clade to reinstate the subspecies name for it, pending further investigation that may result in raising it to full species status. For the Antarctic clade, the name G. chilensis chilensis should be used for the time being, although the type locality is in Southern Chile, and if future molecular data find the Chilean population to be in the same clade as the New Zealand and South China Sea material, a new name would need to be found for the Antarctic clade. The only morphological difference between the two subspecies mentioned by Mortensen (1924) is a sparser distribution of the dorsal disc granules in G. chilensis novaezelandiae. The specimen from the present study is smaller and thus probably younger than the holotypes of both subspecies and the New Zealand specimens described by Baker (1980) and McKnight (2000). However, McKnight (2000) also reported two specimens of the same size as ours (16 mm disc diameter) with a dense cover of disc granules. This character may either be variable or age-related. We consider it highly likely that the specimens studied by Baker (1980) and McKnight (2000) represent G. chilensis novaezelandiae. The morphological characters of our specimen varied slightly from their descriptions, particularly in the number of branches in the arms, which is size dependent. According to Baker (1980) the shields indirectly contributed to thickening the periphery of the disc, but other species of Gorgonocephalus showed a distinct gap in granulation at the end of the shields and granules on the periphery of the disc. Therefore, this morphological feature can be used to distinguish G. chilensis within the genus Gorgonocephalus. Considering other morphological characters, G. tuberosus Döderlein, 1902 is similar to G. chilensis by having a dense cover of coarse, conical, or hemispherical granules on the disc, small and closely arranged in the dorsal angle of the interradial space (Döderlein 1902). H.L. Clark (1923), Seno & Irimura (1968) and Mortensen (1936) reported on younger individuals that were attached to the mature adult individuals, which prompted H.L. Clark (1923) to consider G. chilensis as viviparous. Mortensen (1936) suggested that it is not viviparous and these younger specimens simply attached to mature specimens as a host, like larger specimens attach to gorgonians (Olbers et al. 2019). This is the first record of G. chilensis novaezelandiae from the Indo-Pacific region and far from previously recorded occurrences, which may suggest that other non-Antarctic records also belong to this subspecies. Its true bathymetric and geographic distribution is currently unclear, because most previously recorded specimens were reported as G. chilensis and need to be re-examined, preferably with molecular methods. The taxonomic value of the disc granulation should be tested by examination of a large number of specimens, which could also find other distinguishing characters. Distribution 1550–1830 m depth. New Zealand, South China Sea (Mortensen 1924; this study)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 21-25, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Mortensen T. 1924. Echinoderms of New Zealand and the Auckland-Campbell Islands. II. Ophiuroidea. Papers from Dr Th. Mortensen's Pacific Expedition 1914 - 16. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening 77: 91 - 177.","Baker A. N. 1980. Euryalinid Ophiuroidea (Echinodermata) from Australia, New Zealand, and the South-west 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). NIWA Biodiversity Memoir 115: 1 - 79.","Doderlein L. 1902. Japanische Euryaliden. Zoologischer Anzeiger 25: 320 - 326.","Clark H. L. 1923. The echinoderm fauna of South Africa. Annals of the South African Museum 13 (7): 221 - 438.","Seno J. & Irimura S. 1968. Ophiuroidea collected from around the Ross Sea in 1964 with description of a new species. Journal of the Tokyo University of Fisheries 9 (2): 147 - 154.","Mortensen T. 1936. Discovery Reports: Echinoidea and Ophiuroidea. Cambridge University Press, Cambridge, UK.","Olbers J. M., Griffiths C. L., O'Hara T. D. & Samyn Y. 2019. Field guide to the brittle and basket stars (Echinodermata: Ophiuroidea) of South Africa. Abc Taxa 19: 1 - 354. Available from http: // www. abctaxa. be / volumes / volume _ 19 _ fieldguide-brittle-and-basket-stars [accessed 16 Feb. 2022]."]}

Asteroschema horridum Lyman, 1879 Figs 7–8 Asteroschema horridum Lyman, 1879: 66. Asteroschema horridum – Lyman 1882: 275. — Baker 1980: 20, fig. 4. — McKnight 2000: 17, pl. 3. Material examined CHINA • 1 spec.; South China Sea, SE of Zhongsha Islands complex, seamount; 13°58.68′ N, 114°52.09′ E; depth 1550 m; 25 Sep. 2020; collection event: stn SC013; MSV Shenhaiyongshi leg.; preserved in 95% ethanol; GenBank: MZ 198759; IDSSE EEB-SW0005 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 18°41.95′ N, 113°33.08′ E; depth 1070 m; 29 Mar. 2018; collection event: stn SC019; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0033. Description (IDSSE EEB-SW 0005) MEASUREMENTS. Disc diameter 12.5 mm, length of arms from 180 to 191 mm. DiSC. Flat, interradially deeply excavated and small in relation to total body size of specimen. Disc covered with small, tumid, irregular scales, but larger on ventral than on dorsal disc. Conically tumid scales on radial shields, forming tubercles with finely thorny tip (Fig. 7A–B), both shields and tubercles decreasing in size towards disc center. Radial shields thick, swollen, widely separated distally, convergent proximally and with additional smaller scales and tubercles. Genital slits short, vertical on ventral interradii (Fig. 7D). Seven blunt, spearhead-shaped teeth. Jaws covered with swollen scales and no true oral papillae (Fig. 7C–D). Adoral shield obscured by swollen scales, oral shield absent and oral tentacle pore covered by small tube-shaped scales. Entire oral area covered with tumid scales, higher and pointier towards margin of ventral disc (Fig. 7C). ARMS. Narrow, more cylindrical and slightly swollen in first 14–15 free arm segments (Fig. 7E). Dorsal and ventral arm also covered with more trapezoid tuberculous scales, distally tubercles more rounded and less elongated and arms with increasingly banded appearance distalwards (Fig. 7E–I). Tubercles on ventral arm slightly lower and pointier than on dorsal surface. First tentacle pore with zero to one arm spine, on second to fifth arm segments one arm spine at tentacle pores, thereafter two arm spines per pore (Fig. 7G–H). Arm spines cylindrical with thorny tip, innermost spine slightly swollen, longer than arm width, twice as long as outermost spine, with thorny tip. Outermost spine not swollen, half as long as innermost spine, tapered (Figs 7I–J, 8C). COLOR. Pale reddish-brown in alcohol specimen (Fig. 7), slightly stronger color in live specimen. OSSiCLE MORPHOLOGY. Lateral arm plates curved around vertebrae, bearing two strongly outwards curved arm spine articulations with large muscle and nerve openings (Fig. 8A–B). Vertebrae with a streptospondylous articulation, with deep slope between proximal and distal end, ventrally with longitudinal groove along midline, no oral bridge (Fig. 8D–H). Remarks Asteroschema horridum was first described by Lyman (1879), with the Kermadec Islands as the type locality (HMS ‘Challenger’ Expedition). Baker (1980) and McKnight (2000) redescribed it. The specimen from our collection was similar to Lyman’s holotype description, but differs slightly from the descriptions in Baker (1980) and McKnight (2000) in having the start of the second arm spine at the first few arm segments (beyond segments 3–6, usually beyond segment 2). This character varies among species of Asteroschema (Baker 1980). Another morphological variation was shown as the extent of swelling on the proximal arm. In the present study, the small specimen (8.2 mm) had a swollen arm for five to six segments, which is similar to Baker (1980) and McKnight (2000), but they did not mention the diameter of the disc (size of the specimen). The character of having a small, flat disc with tubercleshaped scales is one that distinguishes A. horridum from other species of Asteroschema. Asteroschema horridum is considered a close relative of A. tumidum Lyman, 1879 according to morphological aspects (Baker 1980; McKnight 2000). Previously published descriptions suggested that the morphological characters of A. horridum may vary with the size and maturity of the specimens (Baker 1980; McKnight 2000). Distribution 300–2000 m depth. South China Sea, Kermadec Islands and Norfolk Island (New Zealand), New Caledonia, Vanuatu (Coral Sea), French Polynesia (Baker 1980; McKnight 2000; OBIS 2021). Family Gorgonocephalidae Ljungman, 1867 Subfamily Gorgonocephalinae Döderlein, 1911 Genus Gorgonocephalus Leach, 1815, Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 18-21, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Lyman T. 1879. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part II. Bulletin of the Museum of Comparative Zoology 6 (2): 17 - 83.","Lyman T. 1882. Report on the Ophiuroidea. Report of the Scientific Results of the Voyage of H. M. S. Challenger 1873 - 76, Zoology 5 (1): 1 - 386.","Baker A. N. 1980. Euryalinid Ophiuroidea (Echinodermata) from Australia, New Zealand, and the South-west 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). NIWA Biodiversity Memoir 115: 1 - 79.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021].","Doderlein L. 1911. Uber japanische und andere Euryalae. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse Suppl. 5 (2): 1 - 123."]}

Ophiacantha vorax Koehler, 1897 Figs 29–30 Ophiacantha vorax Koehler, 1897: 353–356, pl. 8 figs 68–69. Ophiacantha anchilabra H.L. Clark, 1911: 204–206, fig. 95. Ophiacantha vorax – Koehler 1899: 62, pl. 7 figs 52–54; 1922a: 63, pl. 15 figs 4–5. — Liao 2004: 122–123, fig. 59. Ophiacantha anchilabra – H.L. Clark 1915: 196. — Matsumoto 1917: 117. Material examined CHINA • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°59.21′ N, 111°01.17′ E; depth 1500 m; 1 Apr. 2018; collection event: stn SC020; MSV Shenhaiyongshi leg.; preserved in -95°C ethanol; GenBank: MZ 198765, MZ 203267; IDSSE EEB-SW0011 • 1 spec.; South China Sea, SE of Hainan Island, sea plain; 18°26.13′ N, 111°49.09′ E; depth 1576 m; 26 Jun. 2019; collection event: stn SC001; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198766, MZ 203268; IDSSE EEB-SW0012 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°17.60′ N, 110°34.18′ E; depth 1500 m; 2 Apr. 2018; collection event: stn SC021; MSV Shenhaiyongshi leg.; preserved in -80°C; IDSSE EEB-SW0045. Description (IDSSE EEB-SW 0011) MESUREMENTS. Disc diameter 6.2 mm. DiSC. Sub-pentagonal, covered by skin with underlying scales, bearing four to six short, stump-like spines with crown of sharp, straight thorns and a few elongated thick, thorny stumps in the center (Fig. 29A–F). Radial shields long, narrow, widely separated, slightly convex, distal end thickened and exposed (Fig. 29A). Radial shields concealed by thin skin and thorny stumps, but clearly visible through skin when specimen dried (Fig. 29A). Dorsal arm plate on first arm segment covered by thorny stumps (Fig. 29D). Ventral disc also covered by thorny stumps, but less dense than on dorsal disc, scales clearly visible, genital slits short (Fig. 29F). Oral shield triangular, much wider than long, distal end slightly convex, proximal edges concave or straight (Fig. 29B), madreporite larger, as long as wide, distal edge strongly convex (Fig. 29G). Adoral shields narrow, curved, three times as long as wide and not separated, bordering proximal edges of oral shield, not separating it from arm (Fig. 29G). Jaws elongated, with one large pointed ventralmost tooth and three long, spiniform, pointed lateral oral papillae on each side, distalmost papilla wider than other two (Fig. 29G). ARMS. Dorsal arm plates triangular, distal edge convex, separated (Fig. 29I). Ventral arm plate on first arm segment small, wider than long, slightly triangular with concave distal edge. Second ventral arm plate pentagonal, wider than long, with obtuse proximal angle, excavated lateral edges and slightly convex distal edge. Following plates as wide as long, distalwards becoming wider than long, slightly hexagonal, with curved distal edge and angular proximal edges, separated except on second arm segment (Fig. 29H, J). Lateral arm plates meeting above and below. Six smooth arm spines, three dorsal and three ventral. Dorsalmost arm spine one and a half to two arm segments in length, second dorsalmost arm spine longest and meeting across dorsal midline (Fig. 29I–J). Ventral arm spines similar in length, with finely thorny surface (Fig. 29K). One elongated tentacle scale, large, often as long as ventral arm plate (Fig. 29H). COLOR. When alive, entire specimen light brown, darker brown when dry (Fig. 29). OSSiCLE MORPHOLOGY.Arm spine articulations well-developed, placed at an angle on separate, protruding distal part of lateral plate, bordered by a wavy ridge, middle articulations largest (Fig. 30A–B). Arm spine with thorny surface (Fig. 30C). Volute-shaped perforated lobe in most articulations, reduced in dorsalmost articulation, with large muscle opening and small nerve opening (Fig. 30A–B). Vertebrae with short, well-developed zygospondylous articulation with a broad, shallow dorsal furrow, distally abruptly truncated, podial basins wider than long (Fig. 30D–H). Ambulacral groove widely diverging distally, without oral bridge (Fig. 30H). Remarks The holotype description of the dorsal disc of Ophiacantha vorax (5 mm disc diameter) is slightly different from conditions in our specimen, which has no elongated disc stumps. However, this morphological feature was only found here on one of the 3 specimens collected. Variability in morphological characters (arm spines, extent of thorny stumps on radial shields, tentacle scale) is low in O. vorax (Koehler 1922a). Koehler (1897) considered one of the distinguishing features of O. vorax to be the presence of only six arm spines, but H.L. Clark (1911) and Liao (2004) documented eight to nine arm spines in their specimens. Therefore, the number of arm spines is not a suitable character to distinguish O. vorax from other species of Ophiacantha. Ophiacantha pentagona Koehler, 1897 is related to O. vorax, but differs in having long and thicker oral papillae, strongly moniliform arms and longer ventral arm plates in the middle region of the arm. Ophiacantha vorax closely resembles O. longidens Lyman, 1878 in the shape of the oral papillae and oral shields, as well as in the disc shape, but differs in the arrangement of arm spines, and the shape of the arm plates and tentacle scales. Ophiacantha longidens has flattened arm spines, blunt with a thorny surface. Another species resembling O. vorax is O. duplex Koehler, 1897, recorded from deep waters in Japan, Philippines, Indonesia, Australia and Madagascar. It can clearly be distinguished by its large tentacle scale, less thorny, long, thin arm spines, large dorsal arm plate and the presence of large disc spines, as well as the smaller thorned spines. Distribution 550–1908 m depth. South China Sea, East China Sea, off East Japan, India, Philippines, Indonesia, Makassar Strait and Molucca Sea, Coral Sea and New Zealand (OBIS 2021)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on pages 53-57, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Koehler R. 1897. Echinodermes recueillis par \" l'Investigator \" dans l'Ocean Indien. I. Les ophiures de mer profonde. Annales des Sciences naturelles Zoologie 8 (4): 277 - 372.","Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. United States National Museum Bulletin 75: 1 - 302.","Koehler R. 1899. An Account of the Deep-Sea Ophiuroidea Collected by the Royal Indian Marine Survey. Trustees of the Indian Museum, Calcutta.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","Clark H. L. 1915. Catalogue of recent ophiurans, based on the collection of the Museum of Comparative Zoology. Memoirs of the Museum of Comparative Zoology at Harvard College 25 (4): 164 - 376.","Matsumoto H. 1917. A monograph of Japanese Ophiuroidea, arranged according to a new classification. Journal of the College of Science, Imperial University, Tokyo 38: 1 - 408.","Koehler R. 1922 a. Ophiurans of the Philippine seas and adjacent waters. United States National Museum Bulletin 5 (100): 1 - 480.","Lyman T. 1878. Ophiuridae and Astrophytidae of the \" Challenger \" expedition. Part I. Bulletin of the Museum of Comparative Zoology 5 (7): 65 - 168.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}

Ophiomusa lymani (Wyville Thomson, 1873) Figs 13A–G, 14 Ophiomusium lymani Wyville Thomson, 1873: 174–175, fig. 33. Ophiomusium lymani – Koehler 1904: 58; 1922b: 411, pl. 86 figs 5, 7–9. — H.L. Clark 1911: 107–108; 1923: 364. — Matsumoto 1915: 289. — Olbers et al. 2019: 72–74 fig. 51. Ophiomusa lymani – Hertz 1927: 103–105. Material examined CHINA • 1 spec.; South China Sea, E of Hainan Island, seamount; 18°24.45′ N, 114°52.09′ E; depth 1911 m; 12 Mar. 2020; collection event: stn SC005; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198762; IDSSE EEB-SW0008 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°39.60′ N, 110°36.42′ E; depth 917 m; 1 Sep. 2017; collection event: stn SC015; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198763; IDSSE EEB-SW0009 • 1 spec.; South China Sea, SE of Hainan Island, seamount; 17°06.00′ N, 110°58.20′ E; depth 1500 m; 23 Mar. 2018; collection event: stn SC017; MSV Shenhaiyongshi leg.; IDSSE EEB-SW0034. Remarks We recorded three specimens from the South China Sea at 917 m to 1911 m depth. Disc diameter ranges from 17 to 20 mm. The specimens are similar to the holotype description by Wyville Thomson (1873) and to the first description from the South China Sea in Liao (2004) (Fig. 13A–G). The arm spine articulations are placed at the distal edge of the lateral arm plate (Fig. 14A–D). The vertebrae have a long zygospondylous articulation, a short, moderately large podial basin at the proximal end, and are small and narrow at the distal end. The dorsal end of the vertebrae is distally triangular and proximally flattened, with a long longitudinal groove along the midline, without furrow (Fig. 14E–H). The ventral end of the vertebrae has a broad midline longitudinal groove without an oral bridge (Fig. 14G). Ophiomusa lymani has been recorded from deep waters in both the East and South China Seas. Distribution 130–4829 m depth. East China Sea, South China Sea, Arabian Sea, Indonesia, Australia, New Zealand, Chile, Gulf of Mexico, Caribbean, Atlantic Ocean and South Africa (Olbers et al. 2019; OBIS 2021)., Published as part of Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, pp. 1-95 in European Journal of Taxonomy 810 (1) on page 28, DOI: 10.5852/ejt.2022.810.1723, http://zenodo.org/record/6419522, {"references":["Thomson C. W. 1873. The Depths of the Sea. Macmillan and Co., London. Thuy B. & Stohr S. 2016. A new morphological phylogeny of the Ophiuroidea (Echinodermata) accords with molecular evidence and renders microfossils accessible for cladistics. PLoS One 11 (5): e 156140. https: // doi. org / 10.1371 / journal. pone. 0156140","Koehler R. 1904. Ophiures de l'expedition du Siboga. Part 1. Ophiures de mer profonde. Siboga Expeditie 45 A: 1 - 176.","Koehler R. 1922 b. Echinodermata: Ophiuroidea. Australasian Antarctic Expedition 1911 - 1914, Scientific Report Series C 8 (2): 5 - 98.","Clark H. L. 1911. North Pacific ophiurans in the collection of the United States National Museum. United States National Museum Bulletin 75: 1 - 302.","Clark H. L. 1923. The echinoderm fauna of South Africa. Annals of the South African Museum 13 (7): 221 - 438.","Matsumoto H. 1915. A new classification of the Ophiuroidea: with descriptions of new genera and species. Proceedings of the Academy of Natural Sciences of Philadelphia 67: 43 - 92.","Olbers J. M., Griffiths C. L., O'Hara T. D. & Samyn Y. 2019. Field guide to the brittle and basket stars (Echinodermata: Ophiuroidea) of South Africa. Abc Taxa 19: 1 - 354. Available from http: // www. abctaxa. be / volumes / volume _ 19 _ fieldguide-brittle-and-basket-stars [accessed 16 Feb. 2022].","Hertz M. 1927. Die Ophiuroiden der Deutschen Tiefsee-Expedition. I. Chilophiurida Matsumoto (Ophiolepididae, Ophioleucidae, Ophiodermatidae, Ophiocomidae). Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer Valdivia, 1898 - 1899 22 (3): 59 - 122.","Liao Y. 2004. Echinodermata: Ophiuroidea. Fauna Sinica: Zoology of China Invertebrates 40. Science Press, Beijing.","OBIS 2021. Ocean Biodiversity Information System. Available from www. obis. org [accessed 15 Aug. 2021]."]}