LAKE WHITEFISH

'Lake whitefish', ''Coregonus clupeaformis'', are freshwater whitefish of North America; members of the salmon family. They are found throughout much of Canada and parts of the northern United States of Minnesota and Michigan, including the Great Lakes. A valuable commercial fish, whitefish are also occasionally taken by sport fishermen.
Their colouration is olive-green to blue on the back, with silvery sides. They have a small mouth below a rounded snout, and a deeply forked tail. On average, they reach 18".^[1] They are found in freshwater lakes where they prefer deep, cool water.
Lake whitefish spawn from September through January in water two to four metres in depth. A large spawning migration enters the Athabasca Delta in late summer, moving upstream in the Athabasca River. The longest single movement of a tagged whitefish ever recorded was 388 km (240 miles), from Fort McMurray to the north shore of Lake Athabasca in Alberta Canada.
The Lake whitefish is considered LC(Least Concern) on the conservation list. However, the distinct stock called Lake Simcoe whitefish is considered T(Threatened) on the conservation list. ^[2]
Natural predators include burbot, lake trout and northern pike.
Primarily bottom feeders, lake whitefish eat crustaceans, snails, insects and other small aquatic organisms.

Contents

Lake whitefish and evolution

References

External links

Lake whitefish and evolution

Since the end of the last glaciation (about 12000 years ago), whitefish have been able to re-colonize many North American lakes. As they invaded those environments, they have also diversified into different populations, such that they are now two main ecotypes recognized within the species: a ''normal'' and a ''dwarf'' ecotype. These ecotypes are mainly differentiated by the benthic and pelagic zone they occupy respectively. Normal whitefish also grows much bigger and lives much longer than the dwarf ecotype.
Many of these populations live in sympatry, yet are reproductively isolated. The fact that they are young species makes them prime candidate to study the evolutionary forces driving their ecological divergence and reproductive isolation.

References

1. Average length of whitefish. 12 Aug. 2007
2. Endangered 12 Aug. 2007



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External links

★ Government of Canada, Department of Fisheries and Oceans: Lake Whitefish

★ Government of Alberta Game Fish: Lake Whitefish

★ Fishes of Minnesota: Lake Whitefish