Species Finder Species Posted Mar 13, 2000 Brown Trout Appearance In smaller bodies of freshwater, adult brown trout have a brown or olive-black back, with lighter side colorings and a white belly. Large black spots appear on much of the sides and back, often with lighter borders. Red, yellow, or orange spots with paler borders are also along the sides. Brown trout that swim in large lakes and the ocean lose a lot of their distinctive spots and are a lot more silvery in color. Maximum Size Maximum weight of up to 44 pounds (20 kg), but only in larger bodies of water. Geographic Range Brown trout are originally from Europe and Asia, but were introduced to North America in the late 1800's. Now they can be found in lakes and streams throughout much of the North American continent, apart from the most southerly states and Northern Canada. The biggest brown trout grow in the Great Lakes, especially Lake Michigan and Lake Ontario. Habitat Brown trout thrive in cooler temperatures in clear rivers and lakes. Temperatures between 50-65° F (10-18° C) are ideal, but they can tolerate temperatures 10 degrees warmer. Brown trout are a shy fish and so prefer a lot of cover, especially in streams and rivers. Overhanging vegetation, rocks, stream debris, banks, and deep pools are just some examples of what brown trout like to hide in. Life Span Can be 10-12 years, but reports of fish as old as 18 have been reported. Food Younger brown trout feed on insects primarily, or shrimp if they are sea-runners. As brown trout grow bigger fish becomes their main diet, including whitefish, suckers, shad, and even other trout. Spawning Brown trout mature between three and six years of age. They tend to spawn after brook trout, doing so in late fall and approaching early winter. Females spawn in gravel bottom, covering up their eggs with the use of their fins once finished. Migrations Many brown trout who live in streams move very little, going upstream only to spawn before returning to familiar territory for the rest of the year. Ocean-going trout, however, will travel greater distances for more food options, generally hanging out in estuaries.Brown Trout in the Great Lakes and other bigger bodies of water stay in deep spots during the summer, but migrate to shallower locations in colder seasons, often coming much closer to the surface. Predators Northern pike, bigger trout, birds like heron and osprey, and animals such as mink and otter. Credit for information above: Fisheries and Oceans Canada Fishing For Brown Trout The brown trout is known to be very clever and quite elusive. Attempting to catch one can be a frustrating experience at first. Learning more about this species and understanding its patterns can help you concentrate your efforts in more productive ways. Brown trout feed by day and night and follow an opportunistic feeding style. Their freshwater diet consists of other fish, frogs, mice, birds, streambed invertebrates, and insects that fly near the surface of the water. Fly fishing works very well because these fish rely heavily on insect larvae and pupae, both nymphs and adults. The best way to choose the right trout fly is to try and imitate the natural sources of food at the local trout stream. There are a few reasons that make the pursuit of brown trout a daunting task. Oftentimes, they will prefer to feed at night and stay hidden during the day. When they do feed, they choose secluded areas, staying in one spot rather than chasing their prey. Therefore, when fishing for brown trout, choosing the correct spot is monumental to increasing your chances of success. Getting one on the hook is quite a challenge. Once hooked, the battle is just beginning. These fish are clever enough to try and tangle the line around different obstacles in the water in the hopes of cutting or snapping it. If that fails, the fish will often flop out of the water to attempt a different strategy of escape. Many times, the combination of these strategies succeeds. Information credit: Fisheries and Oceans Canada. Want to know more about Brown Trout? Here's the story behind the current world record.