Arctic cisco (Coregonus autumnalis)

Latin name

Coregonus autumnalis

Other name

Arctic omul

Identification

The back of the Arctic cisco is rather high and slightly curved. The pelvis has an axillary process. This fish has a relatively small head with a not too prominent snout. It has no teeth on the jaw or tongue. Vertebrae: 64-67. Gill lobes: 41 to 48 on 1st gill arch.

Features of fish fins

Dorsal spines (total): 0; Dorsal soft rays (total): 10 - 12; Anal spines: 0; Anal soft rays: 12 - 14.

Fish colouring

The Arctic Cisco has a silvery metallic body, a brown or dark green back, and nearly colorless fins.

Distribution

This species is found in the Beaufort Sea, the Colville River Delta, and freshwater areas east of the Sagavanirktok River. It is distributed in several drainages in the Northwest Territories and Siberia, such as the Chaun River, and is rarely found east of Point Barrow.

Habitat

Marine freshwater brackish pelagic-neritic anadromous species. Occurs in brackish waters of coastal lagoons, estuaries, and bays, especially in large flat rivers.

Size

Arctic cisco may reach 50 cm (20 inches) in length and weigh up to 2 kg (4.4 lb), but usually less than 40 cm (16 inches) in length and 1 kg (2.2 lb) in weight. Can live to 13 years or more.

Behavior

The juveniles migrate along the Beaufort Sea coast and then use the wind to reach the Colville River delta, where they are more than 100 miles (160 kilometers) from the spawning grounds. They return to the Mackenzie River to spawn.

Food and feeding habits

Arctic cisco feeds on small crustaceans, insects, small fish, worms and mollusks. At sea, it preys on large crustaceans and small fish. No feeding occurs during upstream migration.

Reproduction

Arctic cisco are capable of laying eggs at the age of 8-9 years. Females do this only two or three times in their lives and not necessarily every year. Breeding occurs in September. It does not breed in Alaskan waters, but does breed in the Mackenzie River. Females can lay up to 90,000 eggs.

Fishing

An important commercial species, but catches and numbers have declined significantly in recent years. These fish are caught in nets.

Relationship with a person

Harmless.