A new species of Rhinogobius gill, 1859 (Teleostei: Gobiidae) from the Bonin Islands, Japan

Abstract

A new freshwater goby, Rhinogobius ogasawaraensis was collected from streams of the Bonin Islands (Ogasawara Group), Japan. The species can be distinguished from all congeneric species by the following combination of characters: (1) meristic features: second dorsal fin rays I, 8-9; pectoral fin rays 18-20; predorsal scales 7-16; longitudinal scale rows usually 32-34; vertebral count 26; and (2) specific colouration: check with some red spots, nape with several longitudinal dark stripes, upper part of pectoral fin base with a horizontal deep brown bar, intermittent dark dotted rows along middle axis of body, no saddle shaped patch of dark dots on dorsal side of body, ventral side of body yellowish white, caudal fin with some dark dotted rows on middle region and the base with a pair of dark brown bars which vertically to each other. The ripe oocyte diameter of this new species suggests that it belongs to a member of typical amphidromous species.