The Caspian goby (Neogobius caspius) is a species of fish endemic to the Caspian Sea where it is only found in brackish waters. It is the largest of the Caspian gobies, and at maximum may reach a length of . References Fish described in 1831 Fish of the Caspian Sea Endemic fauna of the Caspian Sea Brackish water organisms Neogobius Fish of Western Asia