The lake trout is the largest of all North American trout. Gray with pale spots, it commonly grows to 10 pounds or more. They are one of two trout species native to Minnesota (the other is the brook trout).

Identification

General description: The lake trout is a large fish with a typical long trout form. Unlike rainbow and brown trout, it has a forked tail. It also lacks the dark spots that characterize some other trout species.

Size: It is not unusual to catch lake trout weighing 8 to 12 pounds. The Minnesota record is 43 pounds, 8 ounces, caught in Lake Superior in 1955.

Color: Lake trout have gray to black backs with light spots and a lighter underside.

Reproduction

Lake trout begin spawning at 5 to 6 years of age. The females release eggs over rocky lake bottoms allowing the eggs to settle in cracks and crevices of the rocks.

Food

Young lake trout eat plankton and insects that live on the lake bottom. Adults eat fish such as ciscoes and smelt.

Predators

In Lake Superior, larger fish often feed on smaller lake trout. Sea lamprey prey on large lake trout. Mergansers and loons may eat lake trout.

Habitat and range

Lake trout like cold water--45 to 55 degrees F is ideal. They prefer clear, clean lakes surrounded by infertile soils, such as those found in Cook, Lake, and St. Louis counties. In summer they spend their time in the deep parts of the lake, perhaps down to 100 feet.

Population and management

Lake trout were once a valued commercial fish in Lake Superior but were almost eliminated there by the sea lamprey, an exotic fish that attaches itself to other fish and eventually kills them. United States and Canada have worked together to reduce lamprey numbers. Most lake trout lakes are within the Boundary Waters Canoe Area Wilderness.

Fun facts

This fish's Latin name, "namaycush," comes from its Native American Indian name, which means "tyrant of the lakes."