Ryukyu Islands

Rhinogobius giurinus is a goby found through much of China, plus Taiwan, the Korean Peninsula, Japan and the Red and Pha river basins in Vietnam. It appears to exist in a number of forms that differ in colour pattern, morphology or both, and it is unclear whether all of them are conspecific. Newly-imported wild fish tend to be aggressive towards conspecifics, so unlike most Rhinogobius it is best kept in sexed pairs.

Stiphodon surrufus is a small stream-dwelling goby described from Leyte in the Philippines and also reported from Okinawa and Yakushima, Japan. Males are reddish in life and lack elongate spines in the first dorsal fin. It was possibly carried north by the Kuroshio Current, and is less abundant there than congeners such as S. percnopterygionus. Like other Stiphodon it is a specialised algal grazer with an amphidromous life cycle.

Stiphodon alcedo is a small stream-dwelling goby known only from the Ryukyu Islands, Japan, in streams on Okinawa and Iriomote. Nuptial males are blackish or sometimes orange with metallic turquoise on the head, and the male's first dorsal fin is pointed but not filamentous. Like other Stiphodon it is a specialised algal grazer with an amphidromous life cycle.