The rainbow trout, a greenish or bluish trout with spots and a pink stripe down its side, was introduced to Minnesota from the western United States. It likes fast water and is known to leap from the water when hooked.

Identification

General description: This colorful fish is best distinguished by the numerous tiny spots that cover its body and fins and by the pinkish stripe that runs the length of its body.

Size: Minnesota rainbow trout found in rivers are usually less than 5 pounds. However, those found in Lake Superior and some other lakes can grow much larger. The Minnesota record is 16 pounds, 6 ounces. It was caught in the Devil Track River in Cook County.

Color: The rainbow has dark spots on a light background. Its back is olive and its sides have a pink stripe. The tail is covered with small black spots. Those found in lakes are silver.

Reproduction

Rainbow trout begin breeding at age 1 to 5. The females usually take longer to mature than the males. The trout travel upstream to spawn. Female rainbows dig a nest, called a redd, in the spring. Eggs hatch in July. Some varieties that spawn in the fall and winter have been developed through selective breeding.

Food

Young rainbow trout eat insects and crustaceans. Adults mainly eat other fish.

Predators

Brown trout eat rainbow trout. So do people and other predatory birds, mammals, and fish.

Habitat and range

Rainbow trout are native west of the Rocky Mountains. Although they are a cold-water fish, they can survive warmer temperatures than some other trout. They were first stocked in Minnesota in the 1890s. Today they are found mostly in northeastern and central lakes and Lake Superior tributaries. Rainbow trout are stocked in some southeastern Minnesota streams. Rainbows spend their first few years of life in tiny streams, then migrate down to larger bodies of water.

Population and management

Minnesota fisheries managers breed rainbow trout for desirable characteristics such as hardiness and stock them in streams. In some streams managers have installed step pools to help adult rainbows that are traveling upstream to reach their spawning sites. Remote lakes in northeastern Minnesota are stocked from float planes. The fish are dropped from about 300 feet above the lake.

Fun facts

The steelhead, a popular Lake Superior sport fish, is actually a rainbow trout. In April, steelhead swim from the big lake into rivers such as the Knife River to spawn. Then they return to Lake Superior.