Russian Sturgeon

The Russian sturgeon (Acipenser gueldenstaedtii) is a large anadromous species native to the Caspian, Black, and Azov Sea basins, historically ranging into major rivers such as the Volga, Danube, and Ural to spawn. A member of the ancient family Acipenseridae, it has long been one of the most significant sturgeon species in the region. Decades of overfishing, poaching, and river damming have driven the species to critically endangered status, and wild populations have collapsed dramatically since the mid-20th century, prompting extensive international conservation and captive breeding efforts.

The Russian sturgeon can be identified by these traits:

• Short, blunt, rounded snout, less elongated than in many sturgeon relatives
• Four barbels positioned closer to the mouth than to the snout tip
• Robust, cylindrical body shape
• Grayish-green to brown dorsal coloration with a pale belly
• Five rows of bony scutes along the body Its blunter snout and stockier build distinguish it from the smaller, more slender sterlet and from the narrower-snouted green sturgeon. Coloration can vary regionally from more grayish individuals to browner ones depending on local water conditions.

Russian sturgeon inhabit the brackish waters of the Caspian, Black, and Azov Seas, migrating into connected large rivers such as the Volga, Don, Danube, and Ural to spawn. They favor deep channels and slow currents within these inland seas, moving upstream seasonally into freshwater reaches for reproduction. Historic dam construction on major spawning rivers has severely restricted access to traditional breeding grounds, concentrating remaining spawning activity in a small fraction of the species' original range. Some populations also winter in deep pools of the lower river reaches before their spring migration.

Russian sturgeon are opportunistic bottom feeders, consuming mollusks, crustaceans, and small fish located with sensitive barbels. They undertake long upstream spawning migrations in spring, historically traveling great distances up rivers before dams curtailed these movements. Maturation is slow, with individuals not reproducing until well into their second decade of life. The species is now critically endangered, with most surviving populations dependent on hatchery supplementation and strict fishing restrictions to prevent extirpation.