Latin name

Oncorhynchus keta

Other names

Calico salmon, dog salmon, fall salmon, autumn salmon, chum, keta; French: saumon keta; Japanese: sake, shake

Identification

The mouth is large, with the maxillary bone reaching backwards to the vertical of the posterior margin of the eye or even further. The anal fin has 12-15 branched rays. No more than 150 transverse rows of scales. At the beginning of the trip, chum salmon scales are silvery, without spots, then the coloration becomes reddish-yellow and transverse dark purple or dark crimson stripes appear on the sides of the fish (mating attire). The color of the meat is pale and there are dark spots on the body of juveniles. In the ocean, slender, somewhat shrunken chum salmon have a greenish-blue metallic color on the back and silver on the sides, with small black speckles on the top of the sides and back, but no clear black spots. Spawning males turn dark olive or grayish. The blood-red coloration and vertical streaks of green and purple extend up the sides, giving the fish a "chintzy" appearance. It develops the hooked snout typical of Pacific salmon, and the tips of the anal and pelvic fins are often white. By spawning time, the chum salmon's body as well as the palate, tongue, and base of the gill arches become completely black. The teeth, especially those of the male, become enlarged and the meat becomes completely fatless, whitish, and flabby. Two forms are distinguished: summer and fall chum salmon; in Kamchatka, three forms are distinguished - summer, spring, and fall.

Distribution

Chum salmon are the most widely distributed of the Pacific salmon. In North America, they live as far south as about the Sacramento River in California and as far east in the Arctic Ocean as the Mackenzie River in Canada. There they travel all the way to the mouth of the Hay River and the rapids below Fort Smith on the Slave River, enter Big Bear and Big Slave Lakes, and move through the Northwest Territories to the edge of Alberta. It is distributed from Providence Bay to Peter the Great Bay and the Tumen-Ula River along the Asiatic. In the Arctic Ocean, it enters rivers of Siberia - Lena, Kolyma, Indigirka, and Yana - and in Alaska - the Mackenzie River. Numerous in the Bering and Okhotsk Seas, in the Anadyr River, near the coasts of Kamchatka, Sakhalin, the Kuril Islands, and northern Japan (mainly Hokkaido). It was introduced into the rivers of the White Sea and the Baltic Sea, as well as into the Caspian Sea.

Habitat

A migratory fish. Lives 3-6 years in the sea, breeds exclusively in rivers. Spawns once in a lifetime, and dies after spawning. In chum salmon matured in fresh water forms are unknown. Prematurely mature males sometimes occur in American rivers, but they also go into rivers from the sea.

Size

The average weight of a chum salmon is 10 to 15 pounds. Females are usually smaller than males. These fish can reach 40 inches in length and live up to 7 years. The world record for all-tackle fishing is held by a 35-pound specimen from British Columbia. Summer chum salmon are 80 cm long (to the end of the middle rays) and weigh 5.5 kg, fall chum salmon are 100 cm and 10 kg respectively. The length is to the end of the middle rays of the caudal fin.

Life history and Behavior

Chum salmon are anadromous fish and inhabit both oceanic environments and coastal streams. They spawn between 2 and 7 years of age, most often at age 4, and at 5 to 10 pounds. They are sometimes called "fall salmon" because they are among the last of the season to spawn, entering river mouths after mid-June but reaching spawning grounds as early as November or December.

Food and feeding habits

In the ocean, chum salmon feed on a variety of organisms, including herring, pilchards, sand lance, squid, and crustaceans. Adults stop feeding in freshwater. The fry feed on insect larvae, small crustaceans and worms.

Reproduction

According to the timing of spawning, two forms are distinguished: summer (length up to 80 cm) and autumn (length up to 100 cm). Spawning takes place on fine-pebble stony ground, in springs, mostly ice-free, in fast rivers and streams where there are groundwater outlets, at a flow rate of 0.1-0.3 m/s and water temperature from 4 to 14°С. Summer chum salmon spawn early and in the lower reaches of rivers, while autumn chum salmon spawn later and rise higher in the rivers. Spawning grounds of summer chum salmon are located in the tributaries of the Amur River (the Gorin and Amgun rivers and their tributaries). In the last few years, the spawning grounds of summer chum salmon have shifted further down the Amur River. The spawning grounds of autumn chum salmon are located above Khabarovsk, up to and including the Bidzhan River, and especially in the Ussuri tributaries: Khor, Bikin, and Iman. In Kamchatka, spawning grounds are located in fast mountain rivers. Summer chum salmon spawning runs from August to late September. The spawning peak in the Amur River is in August, when the water temperature is about 12 °C at river mouths and 6-7 °C at spawning grounds. In Kamchatka, the spawning peak is later. The spawning season of autumn chum salmon runs from mid-September to the end of October (in Japan until November); peak spawning time is in October when water temperature in the rivers drops to 0°С (beginning of freezing), and in the springs, to 2-4°С. Water depth at spawning grounds is 10 to 100 cm, rarely up to 4 m. The fecundity of summer chum salmon is 1.3-4.8 thousand eggs, on average 2.4-2.6 thousand, in autumn - 3.2-4.3 thousand, on average 3.7 thousand. It enters rivers to spawn in the third-sixth year, in America, some males mature in the second year.