A new species of Ophioconis (Echinodermata: Ophiuroidea) from Ryukyu Islands, southwestern Japan

摘要

Ophioconis claviculata sp. nov. is described on the basis of three specimens collected from Ryukyu Islands, southwestern, Japan. The new species is distinct in having: disc covered by granules; four, sometimes five flat, polygonal oral papillae on each side of jaw; broad and flat teeth with hyaline distal end; spiniform and conical arm spines, two times longer than the corresponding arm segment at the maximum length; oralmost arm spines on proximal portion of arms flattened and clavate; four tentacle scales on third tentacle pore; and ventral arm plate longer than wide, with concentrate lamellar striations. The new species was found under rocks of open water as well as in a dark and medium to low salinity (28 ppt) environment of submarine cave, suggesting that this species tolerate this specific condition.