Acipenser sturio

Author: Linnaeus, 1758

Acipenser sturio Linnaeus, 1758

Status in World Register of Marine Species:
Accepted name: Acipenser sturio Linnaeus, 1758 (updated 2009-06-25)

Diagnosis: snout moderate, but less than 60% of head, tip narrow and pointed. Lower lip not continuous, interrupted at centre; barbels not fringed, halfway between snout tip and mouth but not reaching the latter; gillrakers 18-25. Dorsal finrays 31-43; pectoral fin with a strong spine; anal finrays 22-26. Five rows of scutes, dorsal 9-16, lateral 24-39 on each side, ventral 9-14 on each side, with dense cross-lines of smaller rhombic plates between the dorsal and lateral rows. Colour: back olivaceous blue with golden tints, flanks light with silvery tints, belly white. Size: to 350 cm and 280 kg, males usually 100-150 cm, females 130-215 cm.

Habitat: on bottom, near shore, at 20-50 m, being the only European species to live in fully saline water; solitary at present because rare; sea migrations of more than 1,000 km. Food: crustaceans, molluscs, polychaete worms, small fishes. Reproduction: enters rivers from March/April to June/July, spawning in May to June over stones and gravel.

Distribution: Atlantic coasts from Morocco to northern Norway, including North Sea and Baltic; also, northern coasts of Mediterranean and Black Sea; formerly abundant in all rivers suitable for spawning, but now rare, the most numerous populations being found in the Gironde, Guadalquivir and especially the Rioni rivers (Black Sea—where fishing for it is prohibited). In the north-western Atlantic is the closely related A. oxyrhynchus Mitchill.

Eggs, larvae and young stages. Ehrenbaum, 1894: 67, pl. III (fig. 23-30), pl. IIIa.
Otoliths (sagitta). Shepherd, 1914: 105; 1915: 25, fig. 7 | Frizzell and Exline, 1958: 284 | Weiler, 1959: 148, fig. 45.