Brook Trout, Salvelinus fontinalis

Brook trout

Identifying characteristics: (Native Fish) Brook Trout have a long, streamlined body with a large mouth that extends past the eye. Color variations include olive, blue-gray or black above with a silvery white belly and wormlike markings (vermiculation pattern) along the back. They have red spots sometimes surrounded by bluish halos on their sides. The lower fins have a white front edge followed by black and the remainder being reddish orange. The tail fin is square or slightly forked. During fall breeding time, male Brook Trout will develop a slight hooked jaw and become very bright orange-red along the lower sides which is highlighted by a black vertical stripe along the belly.

The Brook Trout is native to Michigan's waters and has been designated the state fish of Michigan. They can be found throughout most of the state in cold water, spring-fed streams, rivers, lakes and in the Great Lakes. They can be found alongside rocks, under cover of logs, and undercut banks. Larger Brook Trout often inhabit deep instream pools moving to shallow water feed. They prefer temperatures from 43 to 53 degrees Fahrenheit.

Spawning generally occurs in the months of October and November. Mature Brook Trout seek a gravel riffle areas in spring-fed streams, seepage areas of ponds, lake shores with swift currents or groundwater seepages. Female Brook Trout use their tails to create a spawning bed (or redd) in ¼ inch to 1 inch gravel. Redds may measure 1 to 2 feet in size. Female Brook Trout can produce between 100 to 5,000 eggs depending upon the size and age of the individual. After spawning the female covers the eggs with gravel. Brook Trout eggs must stay silt free and get continuous amounts of oxygen rich water in order for the eggs to survive. Depending upon water temperatures, the egg incubation period is 3 to 4 months before hatching into sac fry.

The sac fry remain in the redd until the yolk sac is absorbed. Then, when they are about 1 ½ inches long, they venture away from the redd to feed. Brook Trout take about 1.5 to 2.5 years to mature and they usually do not live longer than 6 years. Brook Trout living in streams reach between 7 to 9 inches in length. Great Lake Brook Trout or coasters can attain larger sizes up to 25 inches and 10 pounds.

Brook Trout have been described as voracious feeders with the potential to consume large numbers seasonally available mayflies, stoneflies and aquatic insects and terrestrial insects. However, they will often feed on whatever is most readily available like zooplankton, crustaceans, worms and fish.

Brook Trout are avidly sought after by sport anglers, for food as well as for the sport. They can be caught by using various baits and lures including worms, crickets, grasshoppers, wet and dry flies, spoons and spinners.

For more information on how and where to catch Brook Trout see our Michigan Fish and How to Catch Them and Better Fishing Waters.

Brook trout graphic courtesy of Joseph R. Tomelleri and copyrighted.