Scientific name: Acipenser gueldenstaedtii
The Russian sturgeon also known as the diamond sturgeon or Danube sturgeon. It is a species of fish in the Acipenseridae family. It is found in Azerbaijan, Bulgaria, Georgia, Iran, Kazakhstan, Romania, Russia, Turkey, Turkmenistan, and Ukraine. It is also found in the Caspian Sea. This fish can grow up to about 235 cm and weigh 115 kg Russian sturgeon mature and reproduce slowly.

The Russian sturgeon is native to the Black Sea, the Sea of Azov and the Caspian Sea. It is an anadromous fish and moves into the river systems that drain into these seas in order to make its way to spawning areas upstream. It is usually found near the bottom in fairly shallow water over sandy or muddy substrates. Adults migrate upstream in the spring or autumn to spawn in shallow pools
This fish can be distinguished by the shape of its snout, its barbels and scale arrangement. The upper surface is greyish-green.