The lake trout's average life span is seven to eight years. The average size of this fish is six pounds and 17 to 27 inches. It may attain a maximum length of 50 inches. The lower fins have white edges, and the tail fin is forked. An adipose fin is present. The body has light spots on a gray background.
The lake trout lives in the deep water of Lake Michigan. This fish reaches maturity at an age of five to seven years. Spawning occurs in winter. The female deposits several thousand eggs which are buried in gravel. Eggs hatch in 120 to 150 days. The lake trout eats fishes, particularly chubs, sculpins, smelt and alewives. Populations of the lake trout were severely depleted by over fishing and attacks by sea lampreys in the 1940s and 1950s. Lamprey control and restocking of lake trout have helped to restore populations.