Fish Facts » Brown Trout
The interior of the mouth is entirely white. Lake run brown trout usually are silver, just like coho. However, once out of the water the typical large round spots, accented by a light colored hollow, begin to show. Normally the anal fin has only 9-10 rays, which separate it from other trout and salmon with the exception of the occasionally caught Atlantic salmon. Habits - In the Great Lakes brown trout are near-shore fish and are taken by shallow water trolling, surf casting or pier fishing. Usually brown trout in the Great Lakes are plumper than their inland lake and stream counterparts (similar to football shape) because of the super abundance of forage in the Great Lakes.
The species can live in a higher temperature than most other trouts, and this is probably why they were introduced to North America. They are a succesful and aggressive species who are permanent residents in most of the regions where they have been released.
Smaller brown trout feed primarily on insects. The most important insects vary with the season but the bulk of them are mayflies, caddisflies, midges or terrestrial insects. Browns in smaller streams are also dependent on food washed from the banks. Small browns select an area for feeding in a drift and do not move from it until a predator is introduced. This foraging site is characterized by a good view of the drift near refuge sites such as deep water or complex structure. Small browns never feed immediately upstream of a larger fish. Large browns' diets are more diverse than that of younger browns. Smaller trout account for 80% of the large brown's diet. The remaining diet consists of large aquatic insects such as Hexagania and Brown Drake (Ephemera simulans) mayflies and larger species of caddisflies (Trichoptera), crustaceans, snails, amphibians, and food washed from the bank. Also, the feeding habits of large browns is primarily nocturnal. They eat whatever is in the immediate area, preferably about 4 inches from the stream's floor in riffles, pools, or eddies. In contrast to young browns, large brown trout do not sit and wait for food, they hunt it actively.
The main economic benefit of brown trout is the sport of fishing for the species. Many people pursue the sport fishing and some flyfish for browns. Many fisherman donate money to conservation groups to keep the sport alive. Also, browns make a delicious meal.
Adult browns are generally 13 to 16 inches (33-40.6 cm) in length, although old individuals can reach a much larger size.
Brown trout are native to Europe. The species is found in Iceland and on the Northwest coast of Europe, along the Mediterranean and south to India. They have been introduced to appropriate streams all over the world.
University of Michigan Museum of Zoology Animal Diversity Web, Michigan Charter Boat Association
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