A new species of pagurid hermit crab assigned to the genus Kumepagurus Komai & Osawa, 2012 (Decapoda: Anomura: Paguroidea) from the Kaikata Seamount, Izu-Ogasawara Arc, Japan.

A new pagurid hermit crab species is assigned to the genus Kumepagurus Komai Osawa, 2012, previously represented only by the type species, K. cavernicolus Komai Osawa, 2012, known only from a marine cave on Ryukyu Islands, northwestern Pacific. The assignment is made because of the lack of an accessory tooth on the maxilliped 3 ischium, the operculiform right chela, the presence of two distal corneous claws on the left chela fixed finger, the simple pereopods 4 and the development and structure of the male sexual tubes on both coxae of pereopods 5, all characteristic to the type species of the genus. However, in contrast to K. cavernicolus, K. kaikata n. sp. lacks pleurobranchs on the thoracomeres 5 and 6, and in this regard, Kumepagurus is unusual in the family Paguridae. The generic diagnosis of Kumepagurus is emended to accommodate the new species, which is readily distinguished from K. cavernicolus by the proportionately shorter antennular and antennal peduncles and the right cheliped structure and ornamentation, in addition to the difference in the gill number.