Comanthus kumi, a new shallow-water comatulid (Echinodermata: Crinoidea: Comatulida: Comasteridae) from the Ryukyu Islands, Japan

摘要

A new species of the genus Comanthus A.H. Clark, 1908, is described on the basis of specimens collected from Kume Island and Okinawa Island, the Ryukyu Islands, Japan. Comanthus kumi n. sp. is distinguished from all ten congeners by having extremely elongate arms exceeding 300 mm in length and the colouration in life. The new species concealed its whole body in a crevice or small hole on coral reefs during the day and protruded only several elongate arms on the reef surface at night. This habit suggests that the new species is nocturnal.