Latin name

Coregonus pidschian

Other name

Bottom whitefish, Arctic whitefish or pidschian.

Identification

The body of the humpback whitefish becomes more pronounced with age, growing taller. A well-defined hump is present behind the head. Its snout is short and rounded with a small hump in front of the eyes. The mouth is  Inferior and small. Teeth are absent from the jaws, but small, sparse teeth are present on the lingual plate. The upper jaw protrudes above the lower jaw when the mouth is closed. The maxillary bone is relatively long; its width is less than half its length. The mandible articulates with the skull below the middle of the eye, and its length is less than the height of the caudal peduncle. Vertebrae: 58-63.

Features of fish fins

Dorsal spines (total): 0; Dorsal soft rays (total): 11 - 13; Anal spines: 0; Anal soft rays: 10 - 14.

These fish have a high tail stalk. The anal fin has 3-4 barbed rays and 10-14 soft rays. The edge of the anal fin has a small notch. The caudal fin is notched with pointed lobes.

Fish colouring

The Humpback whitefish has a silvery-white underside, including its sides, head, and body. The head and trunk are dark gray from above, and the paired fins are light. In large ones, the body has a golden tint. During spawning season, white epithelial tubercles, also known as "pearl rash," cover the head, body, and fins. These tubercles are more visible in males.

Distribution

This fish species is widespread in the rivers of the Arctic Ocean basin, from the Murmansk coast to the Canadian Arctic. Within its range, the existence of semipassable and riverine forms of this fish species is noted.

Habitat

It is a polar marine and freshwater bottom-dwelling species that prefers brackish waters. They inhabit coastal waters near the shore, the lower reaches of slow-flowing rivers, large lakes with tributaries, floodplain lakes, deltas, and river mouths.

Size

Males of this species have a maximum length of 50.0 cm. Their total length is 32.8 cm. The maximum reported age is 14 years.

Behavior

It is a transient species. It migrates more than 1,200 kilometers inland to spawn. It overwinters near river mouths. Some populations live in freshwater and do not migrate.

Food and feeding habits

Adults primarily feed on mollusks, crustaceans, and chironomid larvae.

Reproduction

Some populations rarely travel far upstream, while others may not venture out to sea at all. However, upstream spawning migrations can be extensive. Adults migrate upstream as early as June to spawn in October. It is thought that juveniles hatch in late winter and spring, then move downstream. They return as adults in four to six years.

Fishing

It is a valuable commercial fish. The main method of fishing for it is with fixed and cast seine nets on its spawning migration routes. Winter fishing is not well developed. Due to its excellent taste qualities, it is a popular target for recreational fishing.

Relationship with a person

Harmless. These fish are used for canned food.