A New Species of the Genus Prionomysis (Crustacea: Mysida: Mysidae) from the Okinawa Islands, Southwestern Japan

Abstract

Prionomysis ryukyuensis sp. nov. is described from the shallow waters of Yagaji Island, Okinawa Islands, in the central Ryukyus of southwestern Japan. This species differs from the other three hitherto described species of Prionomysis Tattersall, 1922 in having a single long seta on the distal end of the exopod of the fourth male pleopod. It is furthermore distinguishable from two of its congeners, P. aspera Ii, 1937 and P. australiensis Murano, 1990, by the shorter antennal scale.