English name: Atka Mackerel (Pleurogrammus monopterygius)

Origin: North Pacific Ocean

Overview

Atka mackerel is a schooling marine fish in the greenling family (Hexagrammidae), native to the temperate to subarctic waters of the North Pacific. Despite its common name, 

it is not a true mackerel — the name derives from its schooling behavior and streamlined body shape.

Distribution & Habitat

Major stocks are concentrated in the Northwest Pacific, particularly around the Aleutian Islands, the Kamchatka Peninsula, the Kuril Islands, and the Sea of Okhotsk. 

Atka mackerel form dense schools over rocky bottoms in areas of strong currents, typically at depths of 50 to 250 meters.

Size & Biology

Adults typically measure 30–45 cm (12–18 in) in total length, with a maximum recorded length of about 54 cm (21 in). The species has a lifespan of 10 to 15 years; 

males reach sexual maturity at around 3 years and females at 4 years.

Diet

Primarily planktivorous, Atka mackerel feed mainly on zooplankton — especially copepods — as well as euphausiids (krill) and other small crustaceans.

Reproduction

Spawning takes place from autumn to winter in rocky coastal areas. Females deposit adhesive egg masses in rocky crevices, 

and males guard the nests continuously for four to five months until the larvae hatch — a behavior rare among pelagic schooling fishes.

Commercial Use

Atka mackerel is an important commercial species, with the largest fisheries in Alaska (USA) and the Russian Far East. Its flesh is white, firm, and mild in flavor, 

making it a versatile ingredient. The fish is widely marketed frozen, either whole or as skin-on fillets.