Rhinogobius sagittus Chen & Miller 2008

Diagnosed from all other species of the genus Rhinogobius by the unique combination of the following characters: second dorsal fin with one spine and 8 rays; anal fin with one spine and 7 rays; pectoral fin with 16-17 rays; scale on longitudinal series 29-31; predorsal scales 3-4; vertebrae 10+16 (total 26); gill opening restricted, reaching ventrally near vertical midline of opercle; body side with 5-6 major patches of blackish-brown clusters of irregular small spots in male; caudal fin base with either an arrow-shaped black mark or a rounded black spot in male; dorsal part of snout with a pair of deep red stripes; cheek with an arrow-shaped infraorbital red to brown curve following with 4-5 parallel, oblique brown stripes in male; branchiostegal membrane grayish with 8-10 rounded red spots in male; and pectoral fin with semicircular creamy yellow background, and a median orange spot and vertical orange bar on lower half (Ref. 79879).

Dorsal spines (total): 7; Dorsal soft rays (total): 8; Analspines: 1; Analsoft rays: 7

Inhabits shallow riffles with depth 20-40 cm, substratum of small pebbles and slow to moderate water flow (Ref. 79879).