(Salmo trutta) Native to Europe, Brown trout were introduced to the U.S. in the nineteenth century. They can grow to huge sizes depending on habitat. In a small mountain stream, for example, a 16-inch brown is considered big, while in the broader expanses of some large rivers they can weigh 10 or even 20 lbs.
Browns spawn in the fall, building nests (redds) on gravelly stream bottoms. After the eggs are fertilized, the female covers them with fine gravel. The young hatch the following spring.
Most browns survive by eating aquatic and terrestrial insects, but a significant number of browns over 12 or 13 inches turn to larger prey such as sculpins, dace, crawfish, and even their own fry. They generally feed most actively at night, especially during the summer.