Lake Trout

The lake trout is a truly Canadian species that occurs from the east coast to the west as well as in the north. Almost all of its natural populations are in inland Canadian waters or the Great Lakes. Known in different parts of Canada as the laker, Mackinaw trout, grey trout, salmon trout, togue, touladi and half a dozen other names, the lake trout is a member of the salmon family. It’s one of the largest of the freshwater fish, and has a reputation for being a challenge to catch and of a superb eating quality.

Salvelinus namaycush (Walbaum) The lake trout is known by several common names, including namaycush, mackinaw trout, grey trout, togue and landlocked salmon.

In 1933, the American Fisheries Society appointed a committee, which consisted of outstanding ichthyologists of the United States and Canada, to study the problem of the common and scientific names of fishes. The name lake trout was accepted by the committee as most appropriate for the fish that is discussed in this article. The name land-locked salmon is a misnomer because it more properly belongs to the land-locked variety of the Atlantic salmon.

The lake trout belongs to the same group of fishes as the brook trout and the Dolly Varden trout, – the chars. The name char is said to be derived from the Celtic word, cear (blood), in_ allusion to the right red colour of the lower surface of the body. In the scientific name for lake trout, Salvelinus namaycush, Salvelinus is an old name for char, and namaycush is an Indian name meaning “dweller of the deep”.

The chars are distinguished from trout (steelhead, Kamloops and cutthroat) in that the bone (vomer) in the centre of the roof of the mouth possesses teeth on its head, in the form of a small patch. The scales of the chars are, in general, smaller than those of any other member of the family Salmonidae, and are embedded in the skin to such a degree that they often escape notice. Other distinguishing features of the lake trout are the elongated body, large head, deeply forked tail, numerous pale or light-coloured spots on the back, sides, cheeks, gillcovers, and dorsal and tail lins.

The lower fins are without a black stripe near the leading edges. Coloration of the lake trout varies greatly from lake to lake; they may be greyish, greenish, brownish, and sometimes blackish.

Distribution
The lake trout agrees with other chars in being typically northern in its distribution. It is native to the northern part of North America from the New England states and the Maritimes through the Great Lakes to Minnesota and Wisconsin, and northward from Quebec to the Northwest Territory, British Columbia and Alaska.

Habitat
Depth, temperature and oxygen are the primary factors which determine the suitability of lakes for lake trout. They normally inhabit only lakes with a depth greater than 50 feet. In fact, ‘rocky lakes less than l00 feet deep, unless they are spring fed, do not have sufficient volume of cold Water to carry many trout.

Lake trout show a more decided tendency to live in colder water than brook trout, even when the two species are found in the same lake. The average preferred temperature for lake trout is 50°F. and the range is 40°F. to 65°F. in summer.
When there is no obstacle to their migration, the ling or burbot, the sculpin, the northern sucker and the whitefish are found in association with the lake trout because their requirements of water temperature and depth are similar. Of these
species, however, the whitefish is the one most closely associated with the lake trout.

Habits
In spring, lake trout are widely dispersed in the shallow waters of their habitat but, as soon as the water warms to approximately 59°F ., they seek deeper and colder water. Of all the salmonid fishes, the lake trout is the least disposed to enter salt water, and records of their occurrence in salt water are rare.

In general, lake trout spawn on rocky reefs or shoals. Spawning grounds located on Lake Opeongo were on exposed shores facing the prevailing winds. Lake trout have been found near the spawning grounds when the water temperature was 57°F., and spawning took place at 54°F . In general, the temperature range for spawning is between 58°F. and 44°F.