Gadidae

Polar cod

Boreogadus saida

Arctic silver migrating with the moving ice

• Brown
• Gray
• Silver
• Polar
• Regional distribution
• Marine fish
• Arctic Ocean
• Atlantic Ocean
• Fusiform
• Medium
• Cold-water fish

Holding the icy Arctic marine food web together through remarkable physiological endurance, the polar cod is a specialized cryopelagic gadid that flourishes directly in sub-zero polar waters. Its slender, elongated body displays a brownish-grey or violet back speckled with tiny dark dots, transitioning into silver flanks and a deeply forked caudal fin. Three distinct dorsal fins and two anal fins crown the torso, while the chin features a tiny, rudimentary barbel and a projecting lower jaw. Specialized antifreeze glycoproteins circulating in its blood depress the freezing point of its bodily fluids, allowing it to swim and feed unharmed in freezing seawater down to minus one point eight degrees Celsius. Circumpolar across the Arctic Ocean, Barents Sea, and northern Bering Sea from surface pack ice down to nine hundred meters depth, it is an essential keystone species. Vast shoals forage beneath sea ice on amphipods, copepods, and krill, serving as the primary caloric conduit sustaining ringed seals, narwhals, beluga whales, and seabirds. Maximum recorded total length attains forty centimetres.

Sources: FishBase — Polar Cod, Boreogadus saida