Caspian Sea and a Pleistocene stage, that includes glaciation cycles and the creation of the present Volga River. During the first stage, the Tethys Sea had evolved into the Sarmatian Lake, that was created from the modern Black Sea and south Caspian, when the collision of the Arabian peninsula with Western Asia pushed up the Kopet Dag and Caucasus Mountains, setting definitive south and west boundaries to the Caspian basin. This orogeneic movement was continuous throughout the years, while Caspian was regularly disconnecting from the Black Sea. In the late Pontian, a mountain arch rose across the south basin and divided it
Black Sea sprat Used for food; it has around 12% fat in flesh. It is one of the most abundant fishes in the Sea of Azov. It is important prey for other fishes, particularly the pikeperch. The Caspian tyulka "Clupeonella caspia" has been long considered a subspecies of "C. cultriventris", "C. cultriventris caspia", and a common name "Black and Caspian Sea sprat" was then applied to the whole. Black Sea sprat The Black Sea sprat, "Clupeonella cultriventris", is a small fish of the herring family, Clupeidae. It is found in the Black Sea and Sea of Azov and rivers of its basins: Danube,