Ophiocamax Lyman, 1878

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 39

Genus Ophiocamax Lyman, 1878

Fig. 17

Type species

Ophiocamax vitrea Lyman, 1878 .

Examined species

Ophiocamax vitrea .

Oral GP

Rounded comma-shaped, externally convex, with many thorns, placed at either side of distal lobe of madreporite.

Adradial GP

Bar-like, straight, distally thickened, proximally tapered to a point. Articular structure with one condyle, bordered by half-circular shallow groove. Proximal to condyle a depression and a pore.

Abradial GP

Flat, strong, curved blade-like, as long as adGP, but wider, distal end curved towards adGP, convex abradial edge thicker, proximal end thinner.Articular structure a concave depression with thickened rim. Distal half of ventral edge with pointed thorns.

Oral shields

Proximally wing-like triangular, large distal lobe, creating a spearhead shape, folded along horizontal midline. Madreporite with large hole in midline of inner side.

Radial shield

Large condyle on distal radial corner, bordered by dorso-distal groove.

Remarks

Ophiocamax vitrea is the only species among the here examined Ophiacanthida in which the hole in the madreporite is not near the distal edge. It is unknown whether this is true for other species of Ophiocamax . The strong fold in the middle of the madreporite may have led to the displacement of the hole, but more species need to be studied.

Figures

Fig. 17. Ophiocamacidae O’Hara, Stöhr, Hugall, Thuy & Martynov, 2018. Ophiocamax vitrea Lyman, 1878, SEM, unless otherwise noted. A. Adradial genital plate, dorsal aspect. B. Adradial genital plate, lateral aspect. C. Abradial genital plate. D. Oral genital plates in situ, digital photo. E. Oral shield and genital plates, micro-CT. F. Oral genital plates. G. Radial shield, internal aspect. H. Oral shield, internal aspect. I. Madreporite, internal aspect. Scale bars: A–E, G =0.5 mm; F, H–I =0.1 mm.