Proterorhinus is a genus of gobies native to Eurasia where they occur in the region of the Caspian and Black seas, inhabiting marine, brackish and fresh waters. Until recently, the genus was considered monotypic, only comprising the tubenose goby Proterorhinus marmoratus. Following molecular and further morphological investigations it has been split into several taxa, with distinct distributions in marine vs. fresh waters and in the Black Sea vs. Caspian Sea basins.