Ophiopus Ljungman, 1867

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 64-65

Genus Ophiopus Ljungman, 1867

Fig. 32A–E

Type species

Ophiopus arcticus Ljungman, 1867 .

Examined species

Ophiopus arcticus .

Oral GP

Absent.

Adradial GP

Wrench-shaped adradio-dorsal distal end, single flat distal condyle bordered by groove, separated from round process by deep incision, process finer meshed on adradial side. Proximal half bar-like, with longitudinal groove in abradial surface. On abradial side a longitudinal groove.

Abradial GP

Absent.

Oral shields

Inner side in distal half laterally thinner with smoother, finer porous stereom. Madreporite inner side with large centrodistal opening.

Radial shield

Articular structure a low condyle and groove, large round patch of finer stereom proximal to condyle.

Remarks

Ophiopus arcticus lacks genital slits, which may explain the absence of oral GP and abradial GP.

Figures

Fig. 32. Amphilepidida O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017, family incertae sedis, SEM images. A–E. Ophiopus arcticus Ljungman, 1867. A. adGP, abradial aspect. B. adGP, adradial aspect. C. Radial shield, inner aspect.D. Oral shield, inner aspect.E. Madreporite, inner aspect.F–I. Ophienigma spinilimbatum Stöhr & Segonzac, 2005. F. adGP, adradial aspect. G. abGP. H. Radial shield, inner aspect. I. Madreporite, inner aspect. Scale bar: A–I =0.5 mm.