Takatsu

Rhinogobius flumineus is a goby endemic to Japan, found in central and western Honshu and on the islands of Kyushu and Shikoku. Its entire life cycle takes place in freshwater, in smaller rivers, tributaries and streams, although it occurs alongside amphidromous congeners in places. Two colour forms appear to exist, based on the shape and patterning of the male's first dorsal fin, and its name is sometimes applied to other species.