Ophiomitrella nudextrema (H.L. Clark, 1939 )

O’Hara, Timothy D. & Thuy, Ben, 2025, Seamount ophiuroids from the High Seas of the western Indian Ocean, Zootaxa 5718 (1), pp. 1-88 : 54

publication ID	https://doi.org/10.11646/zootaxa.5718.1.1
publication LSID	lsid:zoobank.org:pub:A97521F7-2BF1-4840-8C22-03AF6B0AE2D2
DOI	https://doi.org/10.5281/zenodo.17891381
persistent identifier	https://treatment.plazi.org/id/3724530A-FFEE-A84D-FF1A-A62A5DFBFF07
treatment provided by	Plazi
scientific name	Ophiomitrella nudextrema (H.L. Clark, 1939 )
status

Treatment

Ophiomitrella nudextrema (H.L. Clark, 1939) View in CoL

Ophiacantha nudextrema Clark, H.L., 1939: 44–45 View in CoL , fig. 6.

Ophiomitrella nudextrema View in CoL . — O’Hara & Stöhr, 2006: 126, fig. 18q.

STUDY MATERIAL. — MD208 : stn DW4881, Walters shoal, Pentes, 33° 16.87´S, 43° 50.69´E to 33° 16.24´S, 43° 50.0599´E, 377–382 m, 2/5/2017: 1 ( MNHN IE.2023.4175) ( DNA code= IE.2023.4175) GoogleMaps . — MD208 : stn DW4890, Walters Shoal, Pentes, 33° 8.7´S, 43° 58.16´E to 33° 8.77´S, 43° 59.13´E, 492–588 m, 4/5/2017: 1 ( MNHN IE.2016.1357) GoogleMaps .

COMPARATIVE MATERIAL EXAMINED. Ophiomitrella nudextrema (H.L. Clark, 1939) : John Murray /157, Maldive Is, 4° 43.48´N, 72° 55.24´E GoogleMaps to 4° 44´N, 72° 54.18´E, 229 m, 6/4/1934, holotype, NHMUK 1948.5 About NHMUK .26.32 . ATIMO VATAE / CP3614 , Sud Cap Sainte Marie , 26° 14´S, 45° 9´E, 250–300 m, 14/5/2010 GoogleMaps , MNHN IE.2007.4178 ( DNA code= IE.2007.4178). Ophiomitrella tenuis ( Koehler, 1904) : EBISCO/DW2607, Plateau des Chesterfield , 19° 33´S, 158° 40.0003´E, 400–413 m, 18/10/2005 GoogleMaps , MNHN IE.2013.6313 ( DNA code=IE.2013.6313).

Distribution. Maldives ( 229 m); Madagascar ( 250–333 m); Walters Shoal ( 377–588 m).

Remarks. The 3 mm dd holotype of this species is characterised by a pentagonal disc; separate broadlytriangular radial shields, with slightly concave sides, naked; disc granules small stumps, centrally becoming trilobed with minute terminal thorns, disc stumps near the marginal interradial midline become lengthened; to 8 short slender arm spines, uppermost to 2 segments in length, lowermost with some thorns; LAPs striated; 3–4 lateral oral papillae; oral shields 2x as wide as long; one oval tentacle scale with a rough tip, to 1/2 segment in length. The MD208 ( 2–3.5 mm dd) specimens are similar, except the smallest (IE.2016.1357, 2 mm dd) has only one elongated disc stump on the interradial slide of the radial shields. The ATIMO VATAE specimen has some taller disc stumps near the centre of the disc also. This species is sister to Ophiomitrella tenuis from the East Indo-West Pacific.