Ophiocreas corali, O’Hara & Thuy, 2025

O’Hara, Timothy D. & Thuy, Ben, 2025, Seamount ophiuroids from the High Seas of the western Indian Ocean, Zootaxa 5718 (1), pp. 1-88 : 12-13

Ophiocreas corali sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:

Fig. 3a – d, f – h

TYPE LOCALITY. Coral seamount, 41° 22.333´S, 42° 54.066´E to 41° 23´S, 42° 54.1´E, 730 m.

TYPE MATERIAL. — JC066 : stn 4 – 12, Coral seamount, 41° 22.333´S, 42° 54.066´E to 41° 23´S, 42° 54.1´E, 730 m, 16/11/2011, holotype: 1 ( NHMUK 2025.25 ); paratype: 1 ( NHMUK 2025.24 ) ( DNA code= JC066-421 ) .

COMPARATIVE MATERIAL EXAMINED. Ophiocreas caudatus Lyman, 1879 : Toudai Motare , Off Katsuura, Japan, 34° 53´N, 140° 32.7´E, 330 m, 4/10/2008 , NSMT E6374 ( DNA code= NSMT E6374 ). Ophiocreas corali AND 003/xx, 36° 8.47´S, 22° 22.73´E, 958 m, 1/5/2014 , SAMC MB-A73811 ( DNA code=A83811). TN228/J2- 382-015, A1 Seamount , Huon, 44° 19.846´S, 146° 53.19´E, 1335 m, 16/12/2008 , MV F168741 ( DNA code= TOH _ 0907). TN228/J2-393-012, Tasman Fracture Zone , 45° 8.351´S, 145° 59.904´E, 1483 m, 12/1/2009 , MV F168737 ( DNA code= TOH _0911). Ophiocreas sibogae Koehler, 1904 : SS03/2008/101, Great Australian Bight , 35° 3.24´S, 133° 57.384´E, 480 m, 9/3/2008 , MV F159746 ( DNA code=F159746). TAN0308/126, South Norfolk Ridge , 33° 23.41´S, 170° 11.58´E, 469 – 526 m, 31/5/2003 , MV F99763 ( DNA code= AB758818 ). TAN0308/133, South Norfolk Ridge , 33° 23.74´S, 170° 13.03´E to 33° 23.4´S, 170° 11.583´E, 465 – 490 m, 1/6/2003 , MV F99767 ( DNA code= F99767 ). Ophiocreas sp. MoV.7378 SS02/2007/77, Cascade 1200m 5, 43° 55.406´S, 150° 27.889´E to 43° 55.778´S, 150° 28.352´E, 590 – 660 m, 10/4/2007, MV F146228 ( DNA code=F146228) .

COMPARATIVE MATERIAL NOT EXAMINED. Ophiocreas glutinosum Döderlein, 1911 : Todai motare, off Katsuura, Chiba Prefecture, Japan, 34° 53´N, 140° 32.07´E, 500 m, 5/3/2009, identified by Okanishi & Fujita (2014), NSMT E6710 ( DNA code= AB758815 ).

Diagnosis. Disc covered in thick skin that obscures the tiny ( 0.2 mm) embedded granules, no lateral oral papillae. Five arms, to 13x the disc diameter, VAPs are small oblong to sausage-shaped plates that are distal to the curved distal corners of the LAP pair, 2 arm spines after the 9 th arm segment, inner larger (to 3 mm in length) with a few apical thorns, basal podia protected by a sheath of skin with a circular opening at the apex.

Description. Holotype 17 mm dd, disc petaloid, indented interradially, covered in thick papillate skin that obscure the underlying granules. Granules dense interradially but rarely touch each other, 0.2 mm wide, 16 – 25 per mm square, spherical to conical with minute thorns; radial shields can be seen as long bar-like raised plates under the skin, widely separate, slightly curved radially, 4.5x longer than wide, range from near the arm sides to ~2/5 dd; ventral disc also covered in thick skin that continues onto the oral/adoral shields and oral plates. Bursal slits vertical in a sunken section of the interradial disc margin. Jaw almost conical and smooth, teeth triangular, tapering to a blunt point, 1.3x as long as wide, no lateral oral papillae.

Arms 220 mm + long, also covered in thick folded papillate skin with similar embedded granules to the disc, arms becoming wider and more robust after 50 mm from the base, basal dorsal surface forms a groove of skin that protects the underlying gonads, radial ribs of the arms formed from the laterodorsal flange of the vertebrae; LAPs are ventral in position, bar-like, meeting centrally, with a swollen outer section that supports the arm spine articulations; there are one to several small circular superficial plates (possibly DAPs) between the LAP and the base of the vertebral flange; the VAPs are small oblong to sausage-shaped plates that are distal to the curved distal corners of the LAP pair, about 1/3 the length of the space between LAP pairs (rest is connective tissue); basal podia protected by a sheath of skin with a circular opening at the apex that the podia emerges from; first arm segment without spines, one arm spine for next 8 segments, thereafter 2 spines, the inner (up to 3 mm long) longer than the outer one (up to 2 mm long), with a clavate dark tip, smooth from the covering of skin; with sharp thorns facing proximally near the spine apex when skin is removed.

Paratype (NHMUK 2025.24) 12 mm dd, is broadly similar to the holotype, except the 2nd arm spine typically starts at the 25th segment. Parts of this animal were treated with bleach revealing the underlying plates. The adoral shields are massive and form part of the distal rim of the ventral disc, contiguous for 2/3 their length interradially, separated distally by the small triangular oral shield. The vertebrae have hourglass (streptospondylous) articulation surfaces ( Fig. 3f ).

Distribution. South Africa ( 958 m), S Australia ( 1335 – 1483 m), Coral Seamount ( 730 m).

Remarks. These specimens were originally named as O. sibogae Koehler, 1904 . However, specimens of that species (at least as recorded from Australia and New Zealand) tend to have smaller VAPs, often a small oval plate that does not touch the LAPs, and longer, more thorny arm spines (see Mortensen, 1924, fig. 1 – 2). Furthermore, O. sibogae has been typically collected at shallower depths, the type locality being the Kei Islands, Indonesia, from 204 m. DNA evidence indicates that O. corali is distinct from Australian/ New Zealand clades of O. ‘sibogae’ that also occur on shallower seafloor than O. corali , and that the distribution of O. corali extends from South Africa to Southern Australia.

Etymology. Named after Coral Seamount, the type locality.

Figures

FIGURE 3. (a–c) Ophiocreas corali sp. nov. holotype NHMUK 2025.25 (a) dorsal disc, (b) arm, lateral view, (c) ventral disc, (d) dorsal view. (e) Ophiocreas lissum NHMUK 2025.26, dorsal view. (f–h) Ophiocreas corali sp. nov. paratype NHMUK 2025.24 (f) vertebra distal view, (g) lateral arm plate, (h) inner arm spine.