Complex sentence: The sterlet ("Acipenser ruthenus") is a relatively small species of sturgeon from Eurasia native to large rivers that flow into the Black Sea, Azov Sea, and Caspian Sea, as well as rivers in Siberia as far east as Yenisei.
Split into simpler sentences: The sterlet ("Acipenser ruthenus") is a relatively small species of sturgeon from Eurasia. It is native to large rivers that flow into the Black Sea, Azov Sea and Caspian Sea, as well as rivers in Siberia as far east as Yenisei.