A New Species of the Hermit Crab Genus Catapaguroides (Crustacea: Decapoda: Anomura: Paguridae) from Shallow Water in the Ryukyu Islands, Japan

A new species of the pagurid hermit crab genus Catapaguroides, C. umbra, is described and illustrated based on four specimens from shallow water in the Yaeyama Islands, southern Ryukyus, and two specimens from Okinawa Island. It is morphologically similar to C. fragilis (Melin, 1939), C. iejimensis Osawa and Takeda, 2004, C. karubar McLaughlin, 1997, C. olfaciens Alcock, 1905, and C. setosus (Edmondson, 1951), but can be distinguished from them by a number of morphological characters. Catapaguroides umbra sp. nov. represents the fifth species of the genus known from Japanese waters and is one of the smallest hermit crab species in the world.