Gorgonocephalus Leach, 1815

Stöhr, Sabine, 2024, Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata), European Journal of Taxonomy 933, pp. 1-98 : 23-24

Genus Gorgonocephalus Leach, 1815

Fig. 7

Type species

Asterias caputmedusae Linnaeus, 1758 .

Examined species

Gorgonocephalus caputmedusae .

Oral GP

Absent.

1 mm.

Adradial GP

Long with bulbous distal end, extending in an L-shape or as a rounded structure fused to abGP; parallel to arm vertebrae, as long as at least nine segments. Distal edge large and flat, no special articular structures, a depression in dorsal surface. Proximal part with deep median furrow, in cross section u-shaped. Fragmented into multiple, different sized pieces during bleaching.

Abradial GP

Small, attaching under proximal edge of bulbous L-shaped part on adradial GP or both fused to form a single structure.

Oral shields

Regular OS absent, but one or several madreporites, thickened, externally with numerous scattered small pores (transverse row of 7–8 pores in G. lamarcki (Müller & Troschel, 1842) , inner side a meshwork of irregular lamellae and openings.

Radial shield

Long, bar-like with widened distal end, ventral side with flat, smooth articular patch at distalmost end, proximal to widened part a concave patch. Dorsal surface wider than ventral bar, creating thin lateral overhanging edges, with scaly appearance and numerous pores where disc granules were attached. Fragmented into several different sized pieces during bleaching.

Remarks

Radial shields and genital plates broke easily during bleaching in Gorgonocephalus .

Figures

Fig. 7. Gorgonocephalidae Ljungman, 1867, Gorgonocephalus caputmedusae (Linnaeus, 1758), SEM images (except A, D, digital images). A. Dorsal disc inner side with radial shields exposed. B. Radial shield distal end, ventrolateral view. C. Radial shield, distal end, ventral view. D. adGP in situ. E–G. adGP, distal end fragments. H. adGP proximal part fragment. I. Madreporite, inner aspect. Scale bars: