Boreogadus saida (Lepechin 1774)

Jaws of about equal length or lower jaw slightly longer. Chin barbel very small. Palatine teeth always absent. Three dorsal fins, two anal fins, all separate from each other; first anal fin base short, less than one-half of preanal distance; caudal fin deeply concave. Pectoral fin reaching beyond end of first dorsal fin; pelvic fin with a slightly elongated ray. Lateral line interrupted along its entire length, variable in position. No lateral line pores on head. Scales small and embedded, not overlapping. Colour: along back brownish, with many fine dark points; sides and belly silvery; fins dusky, with pale margins.

Found throughout the entire north polar basin, around Greenland and Iceland, into Hudson Bay and in the north and northwest Bering Sea.

Reaches 40 cm total length; common to 25 cm.

The Arctic cod is circumpolar and occurs in coastal habitats during both summer and winter. In the Beaufort Sea, it is also found in brackish lagoons and in almost fresh water in river mouths. Although associated with the occurrence of ice (White Sea), the Arctic cod is present in ice-free nearshore waters (Alaska);also found at 50-175 km offshore in the Beaufort and Chulkchi Seas, at depths of 40 to 400 m. This fish is tolerant of widely fluctuating temperatures, salinities, and turbidities. Migration patterns are unknown, except for a prespawning migration to nearshore waters in late summer in the Beaufort Sea. The Barents Sea stock also under-takes winter mass migrations into the White Sea for spawning. In the Beaufort Sea, most mature males are 2 to 3 years old, whereas most mature females are 3 years old. These ages at first maturity are similar to those reported for the northwest Atlantic and Soviet stocks. In Cheshskaya Bay (White Sea), sexual maturity occurs in the 4th to 5th year of life. A predominance of females among older fish is reported in most populations of Arctic cod (74% females in populations of 3 to 6 years old fish). Arctic cod spawns once in its lifetime . Its fecundity is 9 000 to 21 000 eggs, on average 11 900 eggs per females. The spawning season extends from late November to early February in the Beaufort Sea, from end of December to February in Soviet waters, and from January to February (sometimes April) in the White Sea. Although spawning occurs in the coastal areas of the Beaufort Sea and under the shore ice of the White and Barents Seas, the relative importance of nearshore sites compared with regions farther offshore for spawning remains unknown. Because of the unpredictable conditions of its environment, Arctic cod is an r-selected species with early maturity, rapid growth, production of larger numbers of offspring at a given parental size, small body size, high rates of mortality, and shorter life span. Lagoon and coastal fish are larger at each age than those from deep offshore waters, since warmer coastal waters provide more favorable growth conditions. In Simpson lagoon (Beaufort Sea), a 1 year individual may attain 60 mm total length (usually 21 mm), and older fish vary from 45-257 mm (usually 60-170 mm) while the largest fish offshore usually vary from 60-110 mm; the maximum age is 6-7 years.Arctic cod feed mostly on epibenthic mysids and also on amphipods and copepods. For those that are under the ice surface in offshore waters, fish is the principal food item during the winter. Although they prefer to eat mysids, the dietary importance and proportions of the major groups of prey are based on prey availability. For example, the food of some of the specimens examined in the White Sea consisted exclusively of young shrimp.It is an important food-fish for many of the larger mammals and birds of the Arctic seas.

Arctic cod used to be intensively fished by former USSR, Norway, Danish and German Dm Rp vessels using bottom trawl and mid-water trawl. The fishing grounds are the European part of former USSR, Barents and White Seas, and the northwest Atlantic. The fish is pursued from January through May producing massive catches during February. In 1984, world catches totalled 23 709 t, and after that year they declined steadily, although the stocks are little affected by fishing because r-selected species can support higher levels of fishing mortality and have a quicker recovery time. The total catch reported for 1987 in the FAO Yearbook for Fishery Statistics is 11 713 t, all taken by former USSR. In Canadian waters, Arctic cod has a limited commercial value because it is small and apparently not abundant. The flesh is said to be of low quality. It is exploited in a minor way as an industrial fish, but has great potential for increased catches. Its major utilization by Norwegians is for fish meal and oil.The total catch reported for this species to FAO for 1999 was 22 005 t. The countries with the largest catches were Russian Federation (22 005 t).