The sturgeon is a large, migratory fish, weighing sometimes more than three hundred kilograms. It enters the rivers in April and May. Its sides are covered with about 30 plates, the number of the dorsal plates varies from 9 to 13. It spawns between June and July in deep hollows in fast running water. It lays a large number of eggs, which can rise to as much as two and a half million. The adult fish and the embryos stay in freshwater for only a short time. They live on various marine invertebrates, such as crustaceans, worms and molluscs, whilst large sturgeon even hunt fish that live near the sea bed.
Its economic importance in Europe is negligible, although at the end of the last century itused to be abundant in all large rivers. Its gradual disappearance has been the result of intensive fishing and river pollution, as well as the result of an increasing number of large water constructions, which have made it impossible for the fish to migrate upstream. Its importance at the present time is confined to the area around the Black Sea. A closely similar species (A. oxyrinchus) lives along the American Atlantic coastline from the St. Lawrence to the Gulf of Mexico. It too is now relatively rare.
Maximum size and weight: 300 cm, 300 kg. Identifying characteristics: About 30 lateral plates, 9-13 dorsal plates. Barbels not branched, semicircular in cross-section. Snout relatively flat.