Red salmon, blue back, sox, and blueback salmon. The permanent freshwater form of this species are kokanee, kickininee, little redfish, land-locked sockeye, Kennerly’s salmon, silver trout, and yank.
Sockeye salmon are distinguished from other salmonids by the 28-40 long, slender, closely spaced, serrated gill rakers on the lower limb of the first gill arch. Also, there is a fine, black speckling on the back, but no black spots on the back or caudal fin. The pyloric caecae count is <120.
In pre-spawning adults there are no distinct black spots on the back or caudal fins (kokanee sometimes have a few dark marks on the dorsal fin). The dorsal surface of the head and body is a brilliant steel-blue to green-blue with fine, black speckling. The sides are bright silver and the ventral surface is white to silver. The dorsal fin sometimes contains a few dark marks; other fins are clear to dusky on membranes. The flesh is a rich red colour.
In spawning males the head to lower jaw is pale green to olive with black on the maxillary and snout. The lower jaw is white to grey. The back and sides are a bright red to dirty red-grey, and dirty-red to grey on the ventral surface. The dorsal, adipose and anal fins are red and the pectoral, pelvic, and caudal fins are green to black. Females are similar but the body is a darker grey-red colour. In some freshwater populations, and in rare anadromous populations, the spawners are dull green to yellow without the prominent red colouring. There is little difference between kokanee and sockeye salmon, except for the smaller size for kokanee.
The body is elongate, depth about 4 into standard length, deepest below the origin of the dorsal fin, and moderately compressed. Head length about 4.5 into standard length. Mouth is terminal, large, and slightly oblique. The upper jaw extends beyond the posterior margin of the orbit (in breeding males the jaws become larger and hooked). Snout is bluntly pointed, and lips are fleshy. Teeth are small and well developed in both jaws and on the head and shaft of the vomer, palatines, and tongue; no teeth on the basibranchials.
The interorbital space is high, wide, and rounded, its width about 2.8 into head length. Eye diameter is about 6.6 into head length. Gill membranes are free of each other and of the isthmus. Branchiostegals range from 10 to 15. Caudal peduncle is moderately compressed, its least depth about 11 into standard length. Pyloric caecae range from 60 to 115. On the first gill arch are 28 to 40 gill rakers. Scales are cycloid with 125 to 143 scales above the lateral line, and 125 to 145 on the lateral line.
Adipose fin is small, slender, and fleshy. The number of rays in each of the fins are: dorsal, 11-16; anal, 13-18; pectorals, about 16; and, pelvics about 11 (each of the abdominal fins have a free tipped fleshy appendage above its insertion). The caudal fin is moderately forked.
In spawning males the upper jaw forms an elongate hooked snout with enlarged teeth, and a slight hump forms behind the head.