Amphioplus aff. causatus Koehler, 1905

Okanishi, Masanori & Fujita, Yoshihisa, 2019, A comprehensive taxonomic list of brittle stars (Echinodermata: Ophiuroidea) from submarine caves of the Ryukyu Islands, southwestern Japan, with a description of a rare species, Dougaloplus echinatus (Amphiuridae), Zootaxa 4571 (1), pp. 73-98 : 76-77

Amphioplus aff. causatus Koehler, 1905

( Fig. 2 )

Material examined. Ie Island (RUMF-ZE-02036[1], RUMF-ZE-02037[1], RUMF-ZE-02038[1], RUMF-ZE- 02039[1]): “entrance” (RUMF-ZE-02036, RUMF-ZE-02037, RUMF-ZE-02038) and “right hole” (RUMF-ZE- 02039) of the “Unnamed cave”, under coral rubble, approximately 20 m depth, 24 June 2017.

Remarks. The present specimens agree well with the diagnostic characters of Amphioplus causatus Koehler, 1905 in having small and numerous disc scales, long and narrow radial shields, three oral papillae, two tentacle scales ( Koehler, 1905). However, there is a difference in the morphology of the oral papillae: these are flat and polygonal in our specimens, differing from the original description of the type material which has pointed and triangular oral papillae. Further more intensive comparisons are required.

Sampling locality of the specimens. Ie Island, Okinawa Island Group, southwestern Japan.

Figures

FIGURE 2. Amphioplus aff. causatus Koheler, 1905 (RUMF-ZE-02039]). A, aboral view; B, oral view; C, aboral disc and proximal portion of arms; D, oral disc and proximal portion of arms.