Pollock (Theragra chalcogramma) is a marine fish of the cod family. Length up to 77 cm, usually 34-52 cm, weight up to 2.5 kg. It lives in the North Pacific Ocean. Bottom-pelagic fish. Puberty occurs at the age of 4. Spawning is portioned, stretched, from February to July-August. The caviar is small, pelagic. Fertility is 70.6-670.7 thousand eggs. It feeds on crustaceans and small fish. Numerous. An important object of fishing.
The maximum body length is 91 cm, and the weight is 5 kg; the maximum life expectancy is 15 years.
three dorsal fins;
a very short mustache under the lower lip;
the ventral fins are located in front of the pectoral fins;
the color is spotted;
the eyes are big.
This fish lives in cold waters (from 2 to 9 °C), preferring depths from 200 to 300 meters, although it can migrate, descending to depths of 500-700 meters and deeper. Pollock lives about 15-16 years. During spawning, it approaches the shores, swimming into shallow waters with a depth of 50-100 m. Spawning clusters of pollock are very dense. Spawning itself in different places of the Pacific Ocean begins at different times. So, pollock spawning in the Bering Sea happens in spring and summer (from March to September), off the coast of Korea — in winter and spring (from November to March), off Kamchatka - in spring. At the same time, females can spawn even at subzero temperatures (-1.8 °C). Caviar develops in a 50-meter surface layer [source not specified 69 days].
Pollock reaches puberty at the age of 3-4 years, while reaching its maximum weight, which also varies in different areas of fish habitat (from 2.5 to 5 kg).
Along with other pelagic predators (mackerel, cod, tuna, horse mackerel), it finds food at different trophic levels. Pollock feeds mainly on planktonic crustaceans. As it grows, it begins to feed on larger prey, namely small fish (capelin, Asian smelt) and squid. There are cases of cannibalism among pollock — eating larvae and fry of their own species.