Black Sea–Caspian Steppe Terek River. Between these the rivers are caught by the Malka River which is an east-flowing tributary of the Terek. In the west, since the Caucasus Mountains run parallel and close to the Black Sea coast, no significant rivers from this area reach the Black Sea. The western point is the Taman Peninsula. North of the Taman Peninsula the Kuban River, the Beysug River and the Yeya Rivers reach the Sea of Azov, and the long Manych River and the shorter Sal River reach the lower Don. In the north much of the lower Don is under the Tsimlyansk Reservoir
Caspian Sea of aquatic vegetation. This has been attributed to a general lack of seeding material in newly formed coastal lagoons and water bodies. The Caspian turtle ("Mauremys caspica"), although found in neighboring areas, is a wholly freshwater species. The zebra mussel is native to the Caspian and Black Sea basins, but has become an invasive species elsewhere, when introduced. The area has given its name to several species, including the Caspian gull and the Caspian tern. The Caspian seal ("Pusa caspica") is the only aquatic mammal and is endemic to the Caspian Sea, being one of very few seal species that