Brown Trout

[Marc Martyn]

The brown trout is a medium-sized fish, growing to 20 kg (44 lbs) or more in some localities although in many smaller rivers a mature weight of 1 kg (2 lb) or less is common.
Freshwater brown trout range in color from largely silver with relatively few spots and a white belly, to the more well known brassy brown cast fading to creamy white on the fish's belly, with medium-sized spots surrounded by lighter haloes. The more silver forms can be mistaken for rainbow trout. Regional variants include the so-called "Loch Leven" trout, distinguished by larger fins, a slimmer body, and heavy black spotting, but lacking red spots. The continental European strain features a lighter golden cast with some red spotting and fewer dark spots. It is important to remember that both strains can show considerable individual variation from this general description. Early stocking efforts in the United States used fish taken from Scotland and Germany. The Loch Leven strain is more often found in the western United States, while the "German brown" is found more toward the Midwest and East.

Young brown trout feed on insects and other invertebrates such as shrimp, corixa, caddis, stonefly, mayfly, etc. Both larvae and adults are taken and the fish will eat whatever local insect life is abundant at the time. Larger fish are active predators of fish including young brown trout, suckers, sculpins, shad, whitefish and rainbow trout. Larger brown trout will also feed on small terrestrial animals that fall into the water such as baby birds falling from overhanging nests, or even swimming mice/voles. Brown trout sometimes do not actively feed until the late afternoon or early evening but when the weather is cool they will feed during the day as well. The largest browns feed under cover of darkness. Brown trout can be caught with artificial flies, jigs, plastic worm imitations, spinners and other lures.

Brown trout rarely form hybrids, almost invariably infertile, with other species. One such example is the tiger trout, a hybrid with the brook trout.

http://en.wikipedia.org/wiki/Brown_trout