Two new species of the genus Anilocra Leach, 1818 (Isopoda: Cymothoidae) parasitic on reef fishes from the western Pacific.

Abstract

Anilocra harazakii sp. nov. and Anilocra boucheti sp. nov. are described from specimens collected from Pterocaesio marri (Caesionidae) in the northern Ryukyu Islands, Japan and Myripristis kuntee (Holocentridae) off Madang, Papua New Guinea, respectively. Anilocra harazakii sp. nov. is characterized by the combination of the following characters in the female: the elongate narrow body dorsally vaulted; the pleonite 1 concealed by the pereonite 7; the uropod extending that of the angled pleotelson, and its endopod longer than the exopod; and the dactyli of only pereopods 2 and 3 with one nodule on anterior margins. Anilocra boucheti sp. nov. is characterized by the following: body with convex lateral margins; almost part of the pleonite 1 not concealed by the pereonite 7; pleonite 5 with posterolateral acute angle strongly produced; coxa 3 clearly smaller than coxae 1 and 2; the uropod not extending past the posterior margin of the pleotelson with the tip of one of the rami not exceeding the other; and the dactyli of pereopods 1-4 without nodules. Furthermore, the coloration, i.e., the orange body with black margins, of A. boucheti sp. nov. is unique. Bayesian inference tree using partial mitochondrial cytochrome c oxidase subunit I (COI) genes supported the monophyletic clade composed of the members of the genus Anilocra including the two new species. Since the wounds caused by A. harazakii sp. nov. are often hemorrhagic, the isopod might have severe negative effects on the host.