Caspian Bighead Goby

Ponticola gorlap, or the Caspian bighead goby, is a species of goby, a benthic fish native to the Caspian Sea basin. It is widespread in lower parts of many rivers in Iran, and also found in Azerbaijan and Turkmenistan. In Russia, it occurred in the lowest part of the Volga River up to Astrakhan until 1977, but has thereafter spread upstream. In 2000 it was recorded as being established in the Ivankovo and Rybinsk Reservoirs in...