A new species of Chiromantes s. str. (Decapoda: Brachyura: Sesarmidae) from the Ryukyu Islands, Japan, with a note on the identity of Holometopus serenei Soh, 1978

A new species of the genus Chiromantes Gistel, 1848 s. str. is described from the Ryukyu Islands. The new species is distinguished from another species of Chiromantes s. str., C. haematocheir (De Haan, 1833), by having proportionately longer and less setose ambulatory legs, a relatively flatter carapace, larger eyes, proportionally narrower front, relatively broader male sixth abdominal segment, less inflated male chela, and distinct colouration. The present study also regards Holometopus serenei as a junior subjective synonym of C. haematocheir.