The anal fin has three spines. The opercle flap is never greatly elongated as in some other similar species such as the redbreast sunfish Lepomis auritus or the Longear sunfish Lepomis megalotis. However, insect larvae and cladocerans may also be found in their diet. The species is usually found near the bottom in warm water with little current and abundant aquatic vegetation. Redear sunfish normally reach sexual maturity by the end of their second year.
Nests are saucer-shaped depressions in gravel or silt, and are sometimes so close they almost touch.
There are usually one or two peaks of activity during spawning season. Few survive more than six summers. Distribution Originally Redear sunfish were found in the southeastern U.S. from Texas, north to a line even with southern Illinois, and east to the Atlantic Ocean. As a result of introductions, the range has been expanded and now extends west into New Mexico, and north into Michigan, Ohio and Pennsylvania. In Texas the species is native to the eastern two-thirds of the state from the Red River to the Rio Grande.