Brook Trout Facts: Classification, Description & Life Cycle

The brook trout, Salvelinus fontinalis, is a popular sporting fish prized for its sweet and delicate meat. They are native to the north-eastern region of North America and often found in cold, spring-fed brooks, streams, and pools, typically undercover in the shade of a log, rock or undercut bank. They are also known as aurora trout, coaster, Eastern Brook Trout, sea trout, speckled trout and square tail.

Scientific classification

Species:S. fontinalis


Brook trout are long and streamlined, ranging in color from olive green to black. They have a silvery underbelly, and vermiculations, or worm-like markings, along with their backs. Their sides are covered in red spots that have a bluish halo around them, a defining characteristic of the brook trout. Their lower fins are reddish-orange with a white and black front edge. In the fall, when brook trout breed, the male develops a dazzling red-orange color along with his sides. Brook trout have a large mouth that extends past their eye. The tail fin is mostly square, sometimes with a very slight fork. Brook trout usually range in size from about 10 to 15 inches and weigh anywhere from 11 ounces to 2 pounds.

See Also: Splake Trout Information


Although not a true subspecies, there are two different strains of brook trout, mostly categorized based on location. One is a smaller form that is shorter lived and usually found in cold streams and lakes, and the other is a larger, longer-lived form that is more predatory and is associated with larger lakes, rivers, and estuaries. Brook trout can also be bred with lake trout to create the hardy hybrid variety splake trout. They are also bred with brown trout to create the sterile hybrid tiger trout.


Brook trout are native to the eastern waters of North America, from Newfoundland to Minnesota and have been known to naturally range as far south as Georgia. The preferred water temperature is about 55 – 60 degrees Fahrenheit. Brook trout have also been artificially introduced into waterways across North America to the west coast as well as around the world as a sports fish. Once introduced, the brook trout becomes self-sustaining and has the potential to become an invasive species.


Brook trout are fall spawners, typically in the months of October and November. Ideal spawning grounds are the gravel bottoms of streams and springs, strong currents along lake shores and groundwater seepage areas in lake bottoms. The female uses her tail to create a redd or nest and then produces about 100 to 400 eggs. Following the spawning, the female will cover the eggs with the gravel. Eggs will incubate about 2 to 3 months before hatching.


Brook trout are primarily carnivorous and will eat whatever is available to them. Their diet is typically composed of aquatic and terrestrial insects, crustaceans, other fish, worms, and zooplankton. When they share the same habitat as brown or rainbow trout, they tend to feed on the bottom, while the other trout feed on organisms on the surface and in the water column.

Life Cycle

Brook trout respond to the decreased length of day, increasing fall water run-off and cooler temperatures by initiating spawning. Eggs are laid in the redds and incubate over the winter months. They typically hatch in the spring as fry and begin to feed and establish territory. Those that survive the fry stage develop into parr, which begins to resemble young trout. By age 1 or 2, trout become sexually mature and ready to spawn.

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