Redbreast Sunfish

The average length of the redbreast sunfish is around 11 centimetres (4 in) with a record 30.5 centimetres (12.0 in). The record weight for the fish is 0.79 kilograms (1.7 lb). The redbreast sunfish is characterized by a long black opercular flap, which is longer than those of most other sunfish in its range. There are a few blue iridescent vermiculations on the head. Small teeth may be appreciated, mostly on the roof of the mouth. There are faint vertical bars present on the olive-green bodies of both sexes, which may become more apparent as the background coloration changes to blue-green near the lateral line. Males have darker ventral coloration than that of females, ranging from orange-yellow to orange-red. The caudal fin has a shallow fork and may have orange to red pigmentation.

The species' native range is in the eastern United States and Canada, in rivers emptying into the Atlantic Ocean. The redbreast sunfish tends to be more of a cool-river species, but also inhabits freshwater lakes and streams. The species has been introduced as far west as Louisiana and West Texas.

Lepomis auritus has been transplanted to and become established in Germany, Italy, Mexico, and Puerto Rico. The effects of introduced populations of redbreast sunfish on native species are not well studied.

Redbreast sunfish mainly consume immature aquatic insects. Mayflies, small fish, and dragonfly larvae consist of the majority of the sunfish's diet based on stomach content. Small crayfish may also be consumed. Being an opportunistic feeder, the fish competes with other sunfish and larger predatory fish that prey on the same food they do.

Larger piscivorous fish are the main predators of smaller redbreast sunfish. Micropterus species are a major threat to sunfish because of their shared habitat and the availability of the sunfish. The sunfish prefers structures around banks and overhanging branches that provide food, shade, and protection. Lepomis auritus survives best in water with a current and a pH between 7.0 and 7.5. Lack of current, overly acidic, or basic water can dramatically affect the sunfish's survival rate.

Currently, the redbreast sunfish is not on the federal or state endangered or threatened species list. The species is thriving in its natural habitat.