Acrocnida semisquamata ( Koehler, 1914 )

Glück, Franziska U., Stöhr, Sabine, Bochert, Ralf & Zettler, Michael L., 2012, Brittle stars (Echinodermata: Ophiuroidea) from the continental shelf off Angola and Namibia, Zootaxa 3475, pp. 1-20 : 5

Acrocnida semisquamata ( Koehler, 1914)

Fig. 2A, B

West African records. Amphiocnida semisquamata: Koehler 1914: 187 ; Cadenat 1938: 359. Acrocnida semisquamata: Cherbonnier 1957: 167 ; Longhurst 1958: 100; Tommasi 1967: 540; Amphiura (Acrocnida) semisquamata: Madsen 1970: 172 .

Material examined. St. 1: grab sampling, 13°57.468´S, 12°23.682´E; 1 specimen, 3 mm. Depth: 24 m. This species appeared just once and was the only ophiuroid at this station.

Diagnosis. This species is easily distinguished from the other listed Amphiuridae by the presence of marginal and ventral disc scales thickened into fairly short and pointed cones. The apical pair of infradental papillae is distinctly separated from the lateral oral papillae by a wide gap. Arms bear proximal tentacle pores with only a single tentacle scale.

Distribution. Northern West Africa: Guinea –Bissau and southwards, southern West Africa: Angola (13°S, previously found only as far south as 12°S) and northwards, at 5 to 80 m.

Figures

FIGURE 2. A, B, Acrocnida semisquamata; A, dorsal aspect; B, ventral aspect. C, D, Amphioplus aciculatus; C, dorsal aspect; D, ventral aspect. E, F, Amphipholis bananensis; E, dorsal aspect; F, ventral aspect. G, H, Amphipholis squamata; G, dorsal aspect; H, ventral aspect. Scale bars 1 mm.