Brown Trout, Salmo trutta
Identifying characteristics: (Non-Native Fish) Dorsal and adipose fin, broad square tongue with 11 to 12 large teeth, light pectoral fins, square tail, and nine to 10 rays in the anal fin.
Brown Trout is something of a misnomer for many Great Lakes members of this species, since lake-run browns are predominately silver in color. In addition, the body spots are often obscured in lake-dwellers compared to the resident stream dwellers.
Brown Trout are a close relative of the Atlantic Salmon, and were brought to North American waters as exotics. These natives of Europe and western Asia were introduced into New York and Michigan waters in 1883. Brown Trout have thrived in their new home, and have become firmly established in all of Michigan's upper Great Lakes waters.
Lake dwelling Brown Trout are a wary lot. In spring time you will find them in shallow, rocky, boulder-strewn areas, and they prefer a water temperature of 50-65 degrees F. Since Brown Trout spawn in tributary streams in September and October, they begin to take up residence near stream outlets in late summer to early fall. After ascending a particular stream, Brown Trout spawners choose shallow, gravelly or rocky areas. The female creates a shallow depression (redd) in the gravel, in which the spawning fish deposit the eggs and sperm. When the process is completed, the female covers the redd with gravel. The average lake run adult weighs eight pounds, although individuals can grow to be much larger. Young browns are preyed upon by larger fish and by predatory birds such as mergansers and herons. The diet of adult Brown Trout includes insects and their larvae, crustaceans, mollusks, amphibians, small rodents and other fish. They enjoy a rather long life-span it appears, since researchers have observed them at up to 13 years of age.
For more information on how and where to catch Brown Trout see our Michigan Fish and How to Catch Them and Better Fishing Waters.
Brown trout graphic courtesy of Joseph R. Tomelleri and copyrighted.