What's In a Name?
Brown trout: refers to the overall color of the trout
Salmo (sal´-moe) means "salmon of the Atlantic"
trutta (trutt´-tah) means "trout" in Latin
Where Do They Live?
Brown trout are not native to North America. They were introduced
in the eastern USA in 1883 and probably into Minnesota not to
long afterward. They were introduced into many of Minnesota's
stream by 1923. Today, they occur in many of Minnesota's cold-water
streams and lakes and also in Lake Superior. Some of these streams
and lakes have reproducing populations in them. Others are restocked
every few years. Brown trout can live in warmer and more turbid
(cloudier) water than brook trout can. This allows them to live
in the downstream portions of coldwater streams, while brook trout
live in the headwaters. Brown trout frequently are found living
with blacknosed dace, mottled sculpins, white suckers, creek chubs,
common shiners, northern brook lampreys, and American brook lampreys.
How Big Do They Get?
How Long Do They Live?
Brown trout grow fairly rapidly until they reach maturity. Then
they slow down a bit. In Minnesota, brown trout 250-380 mm (10-15
in) long and 1.6-2.5 kg (3.5-5.5 lbs) are fairly common in streams.
Stream browns over 635-mm (25-in.) long and 5.5 kg (12 lbs) are
rare, but in Lake Superior they are often bigger. The Minnesota
state record for this fish is 7.56 kg (16-lbs. 12 oz). Because
brown trout are somewhat resistant to the pressures of fishing,
they can easily get to 5-7 years old.
What Do They Eat?
The brown trout is a very active feeder and it eats a great variety
of foods. It commonly feeds upon land and water insects, zooplankton,
worms, crayfish, small clams, snails, and a variety of small fish
(young trout, sculpins, minnows, and darters). In a few strange
cases, large browns have been known to eat young mink and small
What Eats Them?
The main predators for this secretive trout are bigger trout and
humans. Because of their good taste, size, fighting ability, and
the challenge in getting them to bite, brown trout have become
a favorite of many anglers. Small brown trout are occasionally
preyed upon by otters, mergansers, and in some cases water snakes.
How Do They Reproduce?
Unlike Pacific salmon, brown trout do not die after spawning.
Most will spawn multiple years and often near the same place.
Spawning habits and seasons are similar to the brook trout, except
that brown trout take 3-4 years to mature. Brown trout spawning
season begins in October and goes into December. If there are
no barriers as there are in many North Shore streams, brown trout
swim up into headwater areas to spawn. They usually choose gravel
bottoms often where there are spring seeps and good moving water.
The fish pair up and them the female makes a saucer-shaped depression
in the gravel. The male defends the nest after it is built until
the female is ready. Once the female is ready, she drops into
the nest and the male follows her. Here the female lays the eggs
and the male fertilizes them at the same time. The female then
covers the eggs with the gravel she removed to build the nest.
The two will repeat the process until the female is "spent"
(has laid all of her eggs). After spawning, the parent fish move
back to the water from which they came.
A single female can lay 400-2,000 depending on her size.
Conservation and Management
Brown trout is an exotic species that has become self-sustaining
in some stream and maintained by repeated stocking in others.