Description of a new species of Opistognathus (Perciformes: Opistognathidae) from the southern Japan Sea

Abstract

Opistognathus abei sp. nov. (Perciformes: Opistognathidae) is described on the basis of two specimens (28.5–30.9 mm in standard length) collected from the Oki Islands, Shimane Prefecture, Japan, at a depth of 25–26 m. The new species is characterized by the following combination of characters: posterior end of upper jaw rigid, without flexible lamina; dorsal-fin rays XI, 13; anal-fin rays II, 13; gill rakers 8 + 16 or 17 = 24 or 25; vertebrae 10 + 18 = 28; longitudinal scale rows ca. 40–43; lateral line terminating below 2nd or 3rd soft ray of dorsal fin; cephalic sensory pores comparatively poorly developed, head sparsely covered with small cephalic pores; no scales above lateral line; body scales absent anterior to vertical below 6th or 7th dorsal-fin spine base; vomerine teeth absent; 3rd infraorbital without suborbital shelf; body generally brown, except for white belly, with two longitudinal rows of 6–9 white blotches; head region without blotches, spots, or stripes; dorsal fin generally hyaline to faint brown, with a yellowish-brown stripe through distal edge of spinous part and just below middle of soft-rayed part, and an ocellus between 2nd and 7th spines; anal and caudal fins uniformly hyaline to faint brown; pectoral-fin base with large white oval blotch; pelvic fin uniformly translucent white.