Perch, a name given to several kinds of popular food fish widely distributed throughout the world. However, the true perch is a freshwater fish found only in the United States, Canada, and Europe. It has a relatively long, rounded body. One of its two dorsal (back) fins is spiny, the other soft, and these fins may be separate or joined. True perch in North America include the yellow perch, the sauger, and the walleye.

The yellow perch is one of the best-known food fish in the United States and Canada. In the Great Lakes region it is known as lake perch. It is extensively raised in hatcheries and has been introduced into many areas where it is not native. It is easily caught with almost any kind of fishing tackle. This perch is yellowish, with dark green vertical bars on each side. It is about 12 inches (30 cm) long and weighs about one pound (450 g). It is found in lakes, ponds, and slowly moving streams. The yellow perch feeds on smaller fish, shellfish, and insect larvae. The European perch is almost identical in appearance and habits with the yellow perch.

The sauger weighs up to about eight pounds (3.6 kg). It is a popular food and game fish, found in many large lakes and rivers of North America. It has a white belly and olive-gray sides and back with dark markings. The walleye, or pikeperch, is a larger, related species. The many species of darters, which are small fish found only in North America, are also members of the perch family.

The redfish, which is often marketed as ocean perch, sea perch, or red perch, is not s true perch. For another unrelated fish called perch,

True perches belong to the family Percidae. The yellow perch is Perca flavescens; the European, P. fluviatilis. The sauger is Stizostedion canadense.