THE FISH

The lake trout belongs to the same group of fishes as the brook trout: the chars. It is possible to get trophy-size specimens of this species, as these two records show: a whopping 102-pound monster taken from Lake Athabasca in 1961 and a more "manageable" 65-pound lunker taken in Great Bear Lake in 1970.

They are carnivorous, but when their regular food is not available, they will feed on plankton. However, their growth will be retarded as a result.

Size, Shape and Colour

To distinguish the chars from trout (steelhead, Kamloops, brown) biologists look in the fish's mouth: the bone in the centre of the roof of the mouth, called the vomer, has a small patch of teeth. The scales of the fish are in general smaller than those of the trout and the body is more elongated.

Young lake trout have a slender, streamlined body, the overall length being four to five times greater than the body depth. These proportions change slightly in older fish as they grow more in girth than they do in length. For example, a sampling from Great Slave Lake taken in 1954 showed a ten-year-old fish measuring 22.9 inches and weighing 5.3 pounds but the 20-year-old fish measured 36.5 inches and weighed 21.6 pounds.

The head of the lake trout is large, deep, and broad. The mouth is also large, extending back beyond rather small eyes. Unlike the Arctic char and brook trout, the lake trout has a very slight overbite. Teeth develop on the upper and lower jaw, on the tongue, and on the vomer.

The fin structure of the species is similar to that of the Arctic char and brook trout, having more or less the same shape and number of rays. However, the most prominent feature is the very deeply forked caudal fin. No other member of the char family exhibits this unmistakable trademark.

Coloration of the lake trout varies dramatically from lake to lake, depending on such things as water clarity and bottom structure. For example, the tea-stained waters of the Muskokas produce considerably darker fish than those which inhabit the blue waters of the Finger Lakes or Lake Simcoe.

In general, however, the lake trout may be grayish, greenish, brownish, or blackish. It has dark worm-like markings (vermiculation) on its side and back on an iridescent background color. The belly is whitish. The whole body is amply covered with light spots which are more intense than those of other chars and are more evident on younger fish. The lower fin is trimmed along its leading edge with creams and whites.

Very young trout display distinctive bands of color that run vertically along the sides of the fish. Known as parr marks, these bands may number anywhere from seven to 12. It's very difficult to distinguish young lake trout from young brook trout of similar ages.

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