A new record of Caprella aino (Crustacea: Amphipoda: Caprellidae) from the southeastern waters of Korea, with comparison to Caprella mutica

Abstract

40 species of the family Caprellidae Leach, 1814 are recorded in Korean waters. Caprella aino Utinomi, 1943 was newly collected from seaweed farms from the southeastern waters of Korea. C. aino was firstly reported in Japanese waters in 1943. Adults of C. aino and Caprella mutica Schurin, 1935 are easily distinguished in that C. aino have pereonite Ⅱ and gnathopod Ⅱ without setae and two small tubercles of articulation of gills in pereonite Ⅲ – Ⅳ , while C. mutica do pereonite Ⅱ and gnathopod Ⅱ covered with setae and those of pereonites Ⅲ – Ⅶ with many tubercles. However, subadult C. mutica is hardly distinguishable from C. aino in that tubercles of pereonite Ⅲ are less developed and they have inconspicuous setae of pereonite Ⅱ and gnathopod Ⅱ . Nevertheless, C. aino is distinguished from subadult C. mutica because adult C. aino have dorsal tubercles on pereonite Ⅳ , Ⅴ , Ⅵ , Ⅶ unlike that of C. mutica . We report C. aino as a new record in Korean water with comparison of C. mutica .