Description

Dorsal spines (total): 0; Dorsal soft rays (total): 10 - 15; Anal spines: 0; Anal soft rays: 11 - 19; Vertebrae: 63 - 72. Distinguished by the presence of large black spots on the back and on both lobes of the caudal fin; the young have no parr marks (Ref. 27547). Body fusiform, streamlined, somewhat laterally compressed; moderately, deeper in breeding males (Ref. 1998). Mouth terminal, normally very little oblique but greatly deformed in breeding males, with lower jaw enlarged, turned up at tip, mouth unable to close (Ref. 1998). Adipose fin large; pelvic fins with axillary process (Ref. 27547). Fish in the sea are steel blue to blue-green on the back, silver on the sides and white on the belly; large oval spots present on the back, adipose fin and both lobes of the caudal fin (Ref. 27547). Breeding males become dark on the back, red with brownish green blotches on the sides; breeding females are similar but less distinctly colored (Ref. 27547). Differs from Oncorhynchus mykiss by having the following unique characters: anal fin with 11-15½ (usually 13½ ) branched rays; 177-240 scales in midlateral row; 26-33 gill rakers; large mature males with enormous hump; juveniles lacking parr marks; and lacking pink to red stripe on flank (Ref. 59043).

Common Names

No common names available.

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Chordata

Class: Teleostei

Order: Salmoniformes

Family: Salmonidae

Genus: Oncorhynchus

Species: Oncorhynchus gorbuscha (Walbaum, 1792)

Climate Zone

Location

Biology

An anadromous species which inhabits ocean and coastal streams (Ref. 5723, 86798). Epipelagic (Ref. 58426). Pelagic at the sea. In freshwater, lives in Montane and Piedmont rivers with moderate to fast current and gravel bottom. Spawns in riffles or at head of riffles in shallow water with current up to 1.5 m/s, and clean coarse gravel (Ref. 59043). Spends 18 months at sea after which spawning migration to the natal river or stream occurs; but because the species is less certain of its homing and there is a certain degree of wandering, streams as much as 640 km from natal streams may be used (Ref. 1998, 27547). Upon emerging from the gravel, fry immediately move downstream and remain inshore for a few months before going out to sea. Fry may feed on nymphal and larval insects while in fresh water, but may not feed at all. In the sea, young feed on copepods and larvacean tunicates, its diet shifting to amphipods, euphausiids and fishes as the fish grows (Ref. 27547). Other food include ostracods, decapod larvae, cirripeds, tunicates, dipterous insects (Ref. 1998, 27547). Fry may be preyed upon by birds and mammals while adults by marine mammals and large fish (Ref. 1998). Mostly sold canned (Ref. 1998) but also utilized fresh, smoked, and frozen; also valued for caviar, especially in Japan; eaten steamed, fried, broiled, boiled, microwaved, and baked (Ref. 9988). The smallest of the true salmon (Ref. 12218).

Habitat

freshwater