First record of Ryukyum yaeyamense (Minei, 1973) (Crustacea: Decapoda: Brachyura: Potamidae) from Kohamajima Island, Yaeyama island group, southern Ryukyu Islands, Japan

Abstract

An endangered freshwater crab, Ryukyum yaeyamense (Minei, 1973) (Crustacea: Decapoda: Brachyura: Potamidae), is recorded for the first time from Kohamajima Island, Yaeyama island group, southern Ryukyu Islands, Japan. Kohamajima Island becomes the third distributional island of the species. The morphological characteristics of the species, their habitats, and ecological notes of the species are provided.