Ophiolepis Müller & Troschel, 1840

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 45-47

Genus Ophiolepis Müller & Troschel, 1840

Fig. 21A–L

Type species

Ophiolepis superba H.L. Clark, 1915 .

Examined species

Ophiolepis variegata Lütken, 1856 .

Oral GP

In situ visible as narrow elongated plates latero-distally at OS. Positioned slanted vertically at distal lateral edge of OS. Elongated oval in shape with raised central ridge and slanting sides; ventral edge convex and thickened, dorsal edge straight. Small pore in distal edge.

Adradial GP

Cleaver-shaped, proximal half a thick rod, distal half dorso-adradially with wide blade-like protrusion, single condyle, bordered by deep groove in distal adradial edge. Proximal to condyle a large depression with protruding rim.

Abradial GP

Longer and wider than adGP, rounded scalene triangular, dorsal edge strongly convex and wavy, ventral edge straight, distal end rounded, proximal end tapered to round point, ventral edge thickened into ridge, distally widened. One to two conspicuous pores in distal edge. Attaches broadly to blade-like protrusion on adGP.

Oral shields

Elongated oval with proximal pointed angle, inner side embossed with thin rim. Madreporite similar, with large hole proximo-central in inner side, divided by narrow bridge.

Radial shield

Inner side of distal part embossed with two poorly defined condyles, bordered by short ledge, proximal to embossed part a patch of coarser stereom with finer centre.

Remarks

The protrusion that gives the adGP its cleaver-like shape is present in all species of Ophiolepis that have been examined so far, albeit sometimes less pronounced or shorter than in O. variegata , and the abGP also has a similar shape in all species ( Pineda-Enriquez 2013). The two condyles on the inner RS are more obvious in O. superba than in O. variegata .

Figures

Fig. 21. Ophiolepididae Ljungman, 1867, SEM, unless otherwise noted. A–L. Ophiolepis variegata Lütken, 1856. A. Oral disc, digital image. B. Genital plates at arm. C. adGP, abradial aspect. D. adGP, adradial aspect. E. Radial shield and abGP at arm. F. abGP and adGP articulated. G. abGP, inner aspect. H. Oral shield, inner aspect. I. Madreporite, inner aspect. J–K. Oral GP, uncertain aspects. L. Radial shield, inner aspect.M–P. Ophiotypa simplex Koehler, 1897.M. adGP articulated at arm and under fused radial shields (or radial primary plates). N. oGP, inner aspect. O. oGP, outer aspect. P. Radial shields (or radial primary plates), inner aspect. Scale bars: A–G, L–M, P=1 mm; H–K=0.5 mm; N–O =0.2 mm.