Oncorhynchus Suckley, 1862
Mouth large, lower jaw reaching to or beyond hind margin of eye, upper jaw to or beyond same point; teeth well developed on jaws, tongue, palatines and on both head and shaft of vomer (but deciduous in adults). No distinct gap between orbital bones and anterior margin of pre-operculum. Anal fin with 10-16 branched finrays. Scales small to minute, 120-240 in lateral line. Vertebrae 62-71.
Habitat: pelagic at O-50 m, but deeper in winter, forming dense shoals during spawning run and making considerable migrations; juveniles in estuarine areas for several months before migration to sea. Food: crustaceans (harpacticoids, calanids, amphipods) by juveniles in estuaries of White and Barents Seas; small fishes, squids, euphausiids, amphipods and copepods recorded in Pacific populations; in freshwaters adults do not feed. Reproduction: August-September (a few in Octoberj at 2 years old, very rarely 3 (mid-July to late September in Pacific); adults die after spawning; juveniles leave rivers June-July or later (late spring to early summer in Pacific), spending one year at sea.
Distribution: a Pacific fish introduced into rivers affluent to White and Barents Seas (I956-63, 1967-75). now more widespread, the stocks maintained by both natural spawning and further stocking; well established in rivers from Ob to Finmark, but straying further south; records from southern Norway and south-eastern Sweden may have been strays from stocking in Bay of Riga (Berg, 1977).
Species about 6; in Clofnam area 3.
Recent revisions: Smirnov (1975), Demars (1976), Berg (1977), Solomon (1979).
Species of this genus in the program:
Oncorhynchus gorbuscha
Oncorhynchus keta
Oncorhynchus kisutch