Common Sturgeon
Acipenser sturio
There are 16 Acipenser species living in Eurasia and North America, distinguished from each other by the shape of the mouth and the number and shape of the bony plates in the skin. The Common Sturgeon has a characteristic elongate snout with barbels closer to its mouth than to the tip of the snout. It has 9-13 scutes or bony plates on its back, 24-44 on its sides and 9-11 on its belly. The first ray of its pectoral fin is thicker than the rest. It has a greyish green or greyish brown back, a white belly, dingy white scutes and brownish fins. This is one of the biggest sturgeons, growing relatively fast and measuring about 1.5m when ten years old. The Common Sturgeon originally lived in coastal waters all round Europe and the cast coast of North America and each year the fish migrated up the major rivers to spawn, but today only isolated specimens are caught in west European waters, none migrate up the Rhine and the Elbe any more and only comparatively few are left in the Black Sea and its tributaries. The males reach maturity when seven to nine years old, the females between eight and fourteen. When spawning the females are extremely prolific, the number of eggs varving from one to two million. The fry feed on benthic invertebrates; adult sturgeons feed mainly on fish, but also take molluscs, bristleworms and crabs. In the sea they probably frequent water over a sandy or a clayey bed; at spawning time they do not travel so far upstream as the Great Sturgeon. The Common Sturgeon population is today everywhere so small that its economic importance is minimal. Fishing is not the only reason for its decline and the pollution and destruction of its spawning sites together with dam construction seem to have made it almost impossible for it to increase its numbers again.
Size
up to 3 m
Weight
up to 300 kg
Fin formula
D 31-47, A 21-34
Fecundity
800,000-2,400,000 eggs
Distribution
The Atlantic coast of Europe, the Mediterranean and the Black Sea; also present in the Baltic Sea and in Lake Ladoga and Lake Onega.