First record of Kamaka corophina Ren & Sha, 2013 (Crustacea: Amphipoda: Kamakidae) in Japan

Kamaka corophina Ren & Sha, 2013 (Crustacea: Amphipoda: Kamakidae) individuals were collected from the Ryukyu Archipelago in Southwest Japan. This is the first record of the amphipod in Japan and the fifth species of the genus in Japan. Kamaka corophina is characterized by a swollen peduncular article 4 of the male antenna 2 with a small process at the posterodistal corner, the male gnathopod 2 propodus with an oblique or transverse palm, and the bases of pereopods 5–7 each bearing 5–9 posterior plumose setae. Although the male gnathopod 2 in the original K. corophina from China has only an oblique palm, those in the Japanese specimens have two types of palm.