Lake Whitefish (Coregonus clupeaformis)

Description

Whitefish are widely distributed in the colder lakes and streams of the Northern Hemisphere. Many whitefish species are threatened with extinction and it is illegal to fish for them in some countries and on certain waters. In Saskatchewan, lake whitefish are not yet threatened, and are the main fish taken by commercial fishermen. Although it is primarily a lake-dwelling species, the lake whitefish also enters rivers. It averages about 1.4 kg in size and is characterized by its deep body that is laterally compressed. The color of the body varies from dark bronze to greenish black, a white belly and silvery sides with light colored fins. The whitefish has a sucking mouth, with an upper jaw that overhangs the lower jaw.

Diet

The fish can live to be eighteen years old and can be found in most deep lakes in Saskatchewan, preferring a depth range of 15 m to 46 m. Whitefish feed on bottom organisms such as mollusks, crustaceans, aquatic insects and their larvae. Fly-fishing can be successful in catching this well-muscled fish.

Reproduction

Whitefish reach sexual maturity at about four and a half years. Spawning commences during October or November in shallow waters. Approximately 35 000 to 50 000 unprotected eggs are deposited over rocky bottoms of the shoreward or reef shoals. The parent fish return to deeper water as the eggs incubate. Eggs hatch in late winter or early spring when the water warms. Once the larvae hatch, they concentrate in water by the shore in water of about 30 cm in depth. When they reach a length of more than 2.5 cm, the small fish head for deeper water. Predatory fish take advantage of the location of these young whitefish and devour many.

Habitat

Saskatchewan's northern lakes and rivers are home to this species. Many of the larger lakes in the south area of the province also have whitefish.