Description of a new species of Obliquogobius (Gobiidae: Gobiinae) from the East China Sea off the Ryukyu Islands, southern Japan

Abstract

Obliquogobius trifasciatus sp. nov. (Teleostei: Gobiidae) is described on the basis of three specimens (29.5–30.5 mm in standard length) collected in the East China Sea, northwest of the Ryukyu Islands, southern Japan, in a depth of 115–124 m. The new species is characterized by the following combination of characters: 2nd dorsal and anal fins each with I, 9 rays; head moderate in size, its length 32.8–34.1% of standard length; lateral surface of nape scaled; postorbital pore G of cephalic sensory canal present; gill opening moderate in size, extending anteriorly to level with posterior margin of eye; pelvic fins united medially, with a well-developed connecting membrane (between innermost rays) and frenum (between spines); caudal fin dorsoventrally asymmetrical, lacking a distinct obliquely pointed tip, and with three lowermost branched rays much shorter than other branched rays; three broad black (dark brown in preserved specimens) bands, superposed by yellow chromatophores, on lateral surface of body, anteriormost band located under 1st dorsal-fin base, middle band just behind a vertical line through posterior end of 2nd dorsal-fin base, and posteriormost band on caudal-fin base; a small faint, yellow-tinged dusky blotch on center of caudal peduncle (between middle and posteriormost bands on body); a large black blotch, covering almost entirety of 1st dorsal fin; 2nd dorsal and caudal fins generally pale yellow, without a barred pattern.