Ophiocypris cf. tuberculosus

O’Hara, Timothy D. & Thuy, Ben, 2025, Seamount ophiuroids from the High Seas of the western Indian Ocean, Zootaxa 5718 (1), pp. 1-88 : 60-61

Ophiocypris cf. tuberculosus

Fig. 21g –h

Ophiocypris sp. — Guille & Vadon, 1986: 175, pl. 1(5–6). STUDY MATERIAL. — MD208 : stn DW4887, Walters Shoal, Pentes, 33° 17.23´S, 43° 55.44´E to 33° 16.98´S, 43° 56.6899´E, 599–640 m, 3/5/2017: 1 ( MNHN IE.2016.1365). — MD208 : stn DW4891, Walters shoal, Pentes, 33° 10.8´S, 44° 0.97´E to 33° 11.59´S, 44° 0.97´E, 650–653 m, 4/5/2017: 1 ( MNHN IE.2016.1354). — MD208 : stn CP4903, Walters Shoal, Pentes, 33° 10.78´S, 44° 0.1499´E to 33° 11.44´S, 44° 0.6601´E, 620–642 m, 7/5/2017: 1 ( MNHN IE.2013.17135) ( DNA code= IE.2013.17135) .

COMPARATIVE MATERIAL EXAMINED. Ophiocypris cf. tuberculosus MIRIKY /DW3179, entre Nosy-bé et Banc du Leven, 12° 57.96´S, 48° 9.4302´E to 12° 59.09´S, 48° 9.4698´E, 362– 220 m, 25/6/2009 , MNHN IE.2007.1218 ( DNA code= IE.2007.1218-2). SAYA / DW5430 , SW Saya de Malha , 11° 46.521´S, 61° 9.254´E to 11° 46.359´S, 61° 9.558´E, 267– 265 m, 15/11/2022 , MNHN IE.2023.4213 ( DNA code= IE.2023.4213). Ophiocypris megaloplax ( Mortensen, 1936) : TAN0308/154, West Norfolk Ridge, Wanganella Bank, 34° 37.2´S, 168° 57.03´E to 34° 37.683´S, 168° 58.1´E, 521–539 m, 3/6/2003 , MV F101790 . Ophiocypris tuberculosus Koehler, 1930 : Rinkai /120110(D-105)st1, Sagami Bay , 35° 6.101´N, 139° 34.284´E to 35° 6.684´N, 139° 34.061´E, 218–318 m, 10/11/2012 , NSMT E11798 ( DNA code= Sagami 8). TAN0308/43, North Norfolk Ridge, 26° 25.94´S, 167° 10.87´E to 26° 26´S, 167° 9.63´E, 750–774 m, 18/5/2003 , MV F99771 . TAN1206/90, Site SM2 ac, Whakatane Seamount, Southern Kermadec Ridge , 36° 47.37´S, 177° 27.252´E to 177° 27.36´N, 36° 47.4´W, 1160– 1155 m, 23/4/2012 , MV F193426 ( DNA code=02VA4) .

Distribution. W Indian Ocean ( 220–362 m), S Africa ( 599–653 m), Walters Shoal ( 599–653 m).

Remarks. The size of the MD 208 specimens is 3.3 (IE.2016.1354), 8.5 (IE.2016.1365) and 10 mm dd (IE.2013.17135). The arms on specimen IE.2016.1365 are almost entire, extending 3.5x dd. The oral shields are broken into proximal and distal halves ( Fig. 21h ), characteristic of the genus Ophiocypris . There are 3, rarely 4, very short arm spines. The disc is covered with coarse polygonal multicoloured plates that are covered in some nodules ( Fig. 21g ). This is characteristic of the species O. tuberculosus . However, as Guille & Vadon (1986) have observed, SWIO specimens differ a little from the Indonesian types. On the figured 9 mm holotype, the disc tubercles are small and quite dense, with up to 20 on larger plates. There are even more on the radial shields, where the outer ones form 1–2 regular rings of granules. This is similar to specimens from the Tasman Sea (MV F99771 ), where they measure 0.1 mm in diameter. On the SWIO specimens they are much fewer (to 8) and larger (to 0.2 mm) on the disc plates, although smaller on the radial shields. The SWIO specimens have only one elongate tentacle scale that sits in a notch between the LAP and VAP, whereas the type is described as having two. However, that is possibly a mistake, as the Tasman Sea animals also have one. Unfortunately, the photo of the type is unclear here and we have not physically examined any types. Until specimens from Indonesia are examined or sequenced, we refrain from describing the SWIO specimens as a new species.

The disc plates nodules are less obvious on the smallest SWIO specimens which also have only 2 arm spines on many segments. This approximates the other Ophiocrypis species O. megaloplax which has flat disc plates, 2 arm spines and one tentacle scale. The type of this New Zealand species is also small ( 3 mm dd), and this opens up the possibility that O. megaloplax is the juvenile stage of O. tuberculosus . However, the arms are also very short, up to 2x dd, whereas O. tuberculatus has much longer arms, over 3x dd, and we maintain them here as separate species.

Figures

FIGURE 21. (a–c) Ophiolimna gyrei sp. nov. holotype NHMUK 2025.43 (a) dorsal, (b) ventral, (c) lateral view of mid arm; (d–f) paratype NHMUK 2025.44 (d) dorsal, (e) ventral, (f) arm tip. (g–h) Ophiocypris cf tuberculosus MNHN IE.2016.1365 (g) dorsal disc, (h) ventral disc. (i) Ophiomyces grandis MNHN IE.2016.1372, ventral disc (some abrasion damage on proximal jaws).