Sterlet Acipenser
The Sterlet Acipenser ruthenus is a freshwater species and is the smallest species of sturgeon. It reaches sexual maturity in just 3-8 years with an average life span of 15 years. It originally inhabited the rivers of Eurasia, being widely distributed in rivers flowing into the Caspian, Black, Baltic, White, Barents and Kara Seas and the Sea of Azov. In the Russian Federation, populations are now thought to be virtually extirpated from three Siberian rivers, Ob’, Irtysh and Yenisey, being currently found mainly in the Volga River.