Trout, a popular game fish valued for its flavor and fighting spirit. It is native to the temperate parts of the Northern Hemisphere, but has been introduced in many other parts of the world. Some trout inhabit fresh water only, but others spend part of their lives in the sea. Most trout are brilliantly colored and are marked with contrasting stripes and spots. A mature trout may weigh from one-half of a pound (225 g) to more than 100 pounds (45 kg), according to its species and habitat. Trout belong to the same family as salmon. They are divided into two groups: (1) true trout, which are of the same genus as the Atlantic salmon, and (2) chars. Like salmon, all sea-running trout and some that remain in fresh water swim upstream to spawn, returning to the place where they were themselves spawned. Spawning time varies from fall to early summer, depending on the species.

Rainbow troutRainbow trout are among the most popular game fish.

Most kinds of trout lay their eggs in shallow nests, called redds, which the females scrape out of gravelly steam or lake bottoms. Like other fish, trout spawn from less than 100 to several thousand eggs at a time. The eggs are fertilized by the male as they are deposited, and the female then covers them with gravel. The eggs hatch in 3 to 10 weeks.

Trout feed on insects, crustaceans, mollusks, spawn, and smaller fish. Adults of the large species often eat small birds and mammals. Trout are caught by trolling, baitcasting, spinning, or flycasting, depending on the kind of trout and their habitat. Over-fishing, the introduction of competing species, and the pollution and diversion of waters have decreased the number of trout in the United States. Many trout are hatched and raised in hatcheries.