Ophiomyxa vivipara Studer, 1876

Fig. 24a–c, 25o–s

Ophiomyxa vivipara Studer, 1876: 462 . — Mortensen, 1924: 114, fig. 6b. — Mortensen, 1936: 241–242. — Mortensen, 1941: 6– 7. — Mortensen, 1952: 12. — Manso, 2010: 5, fig. 5a–b. — Lyman, 1882: 246. — Clark, H.L., 1923: 313. — Mortensen, 1933b: 301–304, fig. 27–29.

Ophiomyxa vivipara var capensis Mortensen, 1936: 242 .

Ophiomyxa vivipara capensis . — Clark, A.M., 1974: 482. — Clark, A.M. & Courtman-Stock, 1976: 134–135, fig. 101–102. — Alva & Vadon, 1989: 832. — Olbers et al. 2019: 155–156, fig. 146–147.

STUDY MATERIAL. — JC066: stn 4-37, Coral seamount, 41° 21.7673´S, 42° 54.9067´E to 41° 22.4´S, 42° 54.6´E, 740 m, 20/11/2011: 1 (NHMUK 2025.59) (DNA code= OVC1); 1 (NHMUK 2025.60) (DNA code= OVC2) .

COMPARATIVE MATERIAL EXAMINED. Ophiomyxa serpentaria Lyman, 1883: CE13008/36, Rockall Trough, ‘ North’ Canyon, 54° 3.19´N, 12° 32.45´W, 1361 m , 6/2013, NUI (DNA code= NUI1404 A). Ophiomyxa vivipara Mortensen, 1936: Lara /86, South Africa, 30° 56.31´S, 16° 37.998´E, 337 m, 2/2/2013 , SAMC MB-A82574 (DNA code=A82574) .

Distribution. S America (6–507 m), S Africa (80–755 m), SW Indian Ocean (373–1179 m), E Indo-W Pacific (385–888 m), S Australia (522–2170 m), New Zealand (150–1408 m), St Paul/Amsterdam Is (460–1680 m), Coral Seamount (740 m).

Remarks. The 2 specimens measure 11.5 (NHMUK 2025.60) and 12 mm dd (NHMUK 2025.59). They both have one thin perforated ovoid to rhomboid DAP, similar to that illustrated by Mortensen (1933d, fig. 2) for the very similar species O. serpentaria Lyman, 1883 . There are 2–3 alternating arm spines, the uppermost longest on segments with 3, spine-like in nature with some notable thorns, generally obscured by thick skin. The oral papillae are rounded and wide with denticulate glassy edges. The tube feet have two elongated plates that reinforce the sides (see also Mortensen, 1933d, fig. 3e–f). Neither specimen has any obvious brooded juveniles.

Ophiomyxa vivipara occurs through the temperate Southern Ocean as evidenced by mitochondrial DNA but populations appear to vary in reproduction (O’Hara et al. 2014a). Specimens from around South America have large, brooded juveniles, whilst other populations do not.