Opistognathusctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan.

Opistognathusctenion sp. nov. (Perciformes: Opistognathidae) is described on the basis of three specimens (17.3-30.6 mm in standard length) collected from the Osumi and Ryukyu islands, southern Japan in depths of 35-57 m. Although most similar to Opistognathustriops , recently described from Tonga and Vanuatu, the new species differs in mandibular pore arrangement, dorsal- and caudal-fin coloration, fewer gill rakers, and lacks blotches or stripes on the snout, suborbital region and both jaws.