Salmo salar

Author: Linnaeus, 1758

Salmo salar Linnaeus, 1758

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

Diagnosis: elongate, but becoming deeper with age, caudal peduncle slender, the fish easily grasped by it. Tip of upper jaw reaching to hind margin of eye, but not beyond; jaws in adult males become greatly hooked just before and during breeding. A staggered line of teeth on shaft of vomer, but none on head of vomer. Gillrakers 17-24. Dorsal finrays iiiiv 9-12, and an adipose fin behind it; pelvic finrays i-ii (7) 8-9, base below latter half of dorsal fin; anal finrays iii-iv 7-9 (10); caudal fin fairly deeply forked. Scales small, 114-130 in lateral line, 11-15 obliquely from adipose fin to lateral line. Vertebrae 59-60. Colour: back brown, or green/blue, flanks silvery, belly white; back and flanks above lateral line (rarely below it) with X-shaped black spots; in freshwater, flanks greenish or brown, mottled with red or orange and with large dark spots with lighter edges; juveniles (parr) with 8-11 dark marks on flanks with an orange mark between, but become entirely silvery at migratory stage (smolts). Size: to 150 cm and 39 kg or more, usually 40-130 cm.

Habitat: adults in sea not forming shoals, making considerable migrations, often transatlantic (but life in sea not well known); juveniles in streams, rivers or estuaries. Food: at sea, crustaceans and small fishes (herring, sprat, sand-eels, capelin, small gadids); in freshwater, adults do not feed, but juveniles take mainly aquatic larvae of insects. Reproduction: spawning runs April to August, the adults ascending far upstream, but not actually spawning until October-December at 5-6 years of age. Females dig and shape a 'nest' or redd in the gravel bottom, eggs and sperm are ejected simultaneously and the redd covered; partly grown males (parr) often contribute sperm also; spent adults (kelts) return to the sea, some to spawn the following year, a very few to spawn a third time, and hardly any a fourth time. Juveniles remain in streams and rivers as parr for 1-3 (rarely 4) years before descending as smolts.

Distribution: Atlantic coasts of Europe, from Barents Sea, northern Norway and Baltic southward to northern Portugal, also around Iceland and southern Greenland; not in Mediterranean. Elsewhere, coasts of Canada and North America.

Eggs, larvae and young stages. Roule, 1920: 92-139, fig. 14-54 | Ivanov, 1937: 599, fig. 552-553, 563, 565 | Nikiforov, 1959: 68, fig. 1-5 | Evropeizeva, 1960: 84, fig. 2-5 | Vernidub, 1967: 75, fig. 1a, 2a, 5, 8.
Otoliths (sagitta). Scott, 1906: 76, pl. IIB (fig. 31), pl. V (fig. 9) | Shepherd, 1910: 295, pl. 1 (fig. 14); 1914: 109 | Frost, 1925: 157, pl. XII (fig. 2) | Sanz Echeverría, 1928: 162, pl. IV (fig. 8) | Chaine, 1942: 127, pl. V | Bauzá-Rullán, 1962: 5, pl. 1 (fig. 1-2).