Ophienigma Stöhr & Segonzac, 2005

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 66

Genus Ophienigma Stöhr & Segonzac, 2005

Fig. 32F–I

Type species

Ophienigma spinilimbatum Stöhr & Segonzac, 2005 .

Examined species

Ophienigma spinilimbatum .

Oral GP

Not examined.

Adradial GP

Wrench-shaped adradio-dorsal distal end (condyle separated from process by deep incision), single condyle bordered by shallow groove.

Abradial GP

Sickle-shaped, flat, distally with concave articular structure, almost as long as adGP.

Oral shields

Madreporite with large centrodistal opening.

Radial shield

Single condyle and shallow groove. Patch of finer meshed stereom proximal to condyle.

Remarks

The genital plates and madreporites of Ophienigma spinilimbatum and Ophiopus arcticus show great similarity, which suggests that they are most likely closely related. The wrench shape of the adradial GP is also shared with Ophiactis .

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.