''Ponticola gorlap'', or the Caspian bighead goby, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of goby, a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

fish native to the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

basin. It is widespread in lower parts of many rivers in

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

, and also found in

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

and Turkmenistan.Brian W. Coad
Freshwater Fishes of Iran
(accessed 18 Feb 2015) In Russia, it occurred in the lowest part of the

Volga River The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

up to Astrakhan until 1977, but has thereafter spread upstream. In 2000 it was recorded as being established in the Ivankovo and

Rybinsk Reservoir Rybinsk Reservoir ( rus, Ры́бинское водохрани́лище, r=Rybinskoye vodokhranilishche, p=ˈrɨbʲɪnskəɪ vədəxrɐˈnʲilʲɪɕə), informally called the Rybinsk Sea, is a water reservoir (water), reservoir on the Volga Riv ...

s in the Moscow region, and already invaded the

Don Don, don or DON and variants may refer to: Places *County Donegal, Ireland, Chapman code DON *Don (river), a river in European Russia *Don River (disambiguation), several other rivers with the name *Don, Benin, a town in Benin *Don, Dang, a vill ...

drainage by way of the Volga-Don Canal in 1972. This species occurs in sheltered environments, such as inshore fresh or brackish waters of estuaries, lagoons, lakes and large rivers, where it prefers habitats with a well vegetated rock or firmly packed sand substrate. It can reach a length of SL, and a common size is SL.

External links

Ponticola Fish of Asia Fish of Russia Fish of the Caspian Sea Fish described in 1949 Endemic fauna of the Caspian Sea {{Gobiidae-stub