Redescription of Rhinogobius similis Gill 1859 (Gobiidae: Gobionellinae), the type species of the genus Rhinogobius Gill 1859, with designation of the neotype

Abstract

Rhinogobius similis Gill 1859, type species of the genus, is redescribed (with neotype designation) based on seven specimens collected from the putative type locality (Shimoda, Kanagawa Prefecture, Japan). The species, previously known as R. giurinus (Rutter 1897) (a junior synonym), can be distinguished from its congeners by having the following combination of characters: I, 8 second dorsal-fin rays; 18–19 pectoral-fin rays; 8–12 predorsal scales; 29–31 longitudinal scales; 11 + 15 = 26 vertebrae; predorsal squamation comprising large ctenoid scales, reaching anteriorly to near posterior margin of eye; 5–6 short transverse rows of sensory papillae ventral to eye; several short transverse rows of sensory papillae between two longitudinal rows of sensory papillae on cheek; a dark brownish gray reticulation or reddish oblique lines on head but not on its ventral surface; a black spot, as large as pupil, dorsoposteriorly on pectoral-fin base; a longitudinal series of alternating large and small black blotches on midlateral body; two to four irregular longitudinal rows of small sky-blue spots on midlateral body when alive.