An anadromous species of fish in the family Salmoidae.

Coho salmon (Oncorhynchus kisutch) is a passage fish of the Pacific salmon family. Body length reaches 88 cm, with an average length of 66 cm. It is distributed mainly along the American coast of the North Pacific Ocean. It is a marine fish, forms living freshwater forms. It reaches sexual maturity in the third or fourth year of life. Entry into rivers for spawning is noted in early July - early August. Spawning from early September through March in rivers and springs. Fecundity is about 5 thousand eggs. After spawning it dies. Young Oncorhynchus kisutch in the river initially consume plankton, then young seals, adults in the sea - fish.

Coho salmon is a large fish, reaching a length of 108 cm and a weight of 15.2 kg. The silver salmon is well distinguished from other salmon by the bright silver color of its scales (hence the Japanese and American name - "silver salmon" and the old Russian name - "white fish"). The size of North American fish is larger than those found in the Asian part of the range. 

Asian representatives of the species reach a length of no more than 88 cm and a weight of no more than 6.8 kg. It becomes sexually mature in the third or fourth year of life. Premature maturation of some males has been observed in fresh waters. Coho salmon enter rivers to spawn much later than other salmon species. In Kamchatka, summer, fall and winter coho salmon are distinguished. 

Summer coho spawn in September-October; fall coho spawn in November-December; winter coho spawn in December-January and even in February, and in isolated cases in March. It never spawns in lakes, only in rivers or keys. During spawning, males become dark crimson, while females acquire a much lighter pinkish color. After spawning, all individuals die. The bulk of young fish roll into the sea in the second year of life and very rarely in the third and fourth. It feeds on brookflies, insects, their larvae, eggs and fish fry. 

The marine life period lasts about one and a half years. Passage coho salmon winters in the ocean. In some lakes, it forms a resident form that forms independent populations. The live form reaches sexual maturity in the fourth year of life.