Redbreast sunfish are close relatives of well-known fish species such as the large- and small mouth basses, bluegill, and crappie, all of which are members of the family Centrarchidae. Sunfish typically have compressed bodies and a spinous dorsal fin followed by a soft-rayed fin. These two dorsal fins are joined, so they appear as one. Identification of sunfish is often difficult, especially when closely related species mate to produce hybrids. Adult redbreast sunfish are brownish above with olive green or violet hues. Their heads have lines and spots of a pale blue color, and the flap of the gill cover is black with a pale yellow edge. The sides of the fish are greenish with vertical bars that tend to be more distinct in females than in males. The underside is yellowish white, except during breeding season, when it becomes bright orange in the males and yellow in the females (hence the redbreast sunfish's common name). Redbreast sunfish are more elongated than other Lepomis species and generally attain lengths of up to 25 cm (10 in). The current South Carolina record is 0.9 kg (2 lbs).
Habitat and Biology
This species is commonly found in freshwater habitats from Maine to Florida and westward along the Gulf Coast to Texas. Sunfish are common in the upper blackwater reaches of all rivers and streams in the ACE Basin. The sunfish can survive in a variety of environmental conditions, such as headwater streams to coastal plain rivers and lakes. They prefer flowing water and are most often found associated with stumps or logs in mainstream habitats, but can exist in impoundments. They can survive in lakes and streams at elevations of up to 1,000 meters (3,500 feet) and waters less than 8 ppt. Redbreast sunfish can withstand pH ranges from 4.8 to 8.4; however, they cannot survive in waters warmer than 37° C.
Spawning generally occurs in May and June in the ACE Basin. The full moon of May is the "traditional" time of the peak spawning season. Spawning occurs over sandy or gravel bottoms in lakes, ponds, streams and rivers. When spawning in rivers, this species tends to do so in faster flowing water than other sunfishes. The nest consists of a circular depression on the bottom that is lined with pebbles. Most often it is associated with some type of cover and is in the main channel of the stream. Occasionally, redbreast sunfish will occupy the nests of other species. They do not have community nests like other Lepomis species. Males guard the eggs until hatching and are continually fanning the nest to increase oxygen levels and remove siltation. Sexual maturity is achieved in the second year, and females can lay up to 14,000 eggs. Most redbreast live to an age of three or four years.
Similar to most sunfish, redbreast sunfish are sight feeders and capture food either by lying in wait and making a sudden lunge or by actively foraging along the bottom. Preferred food items of redbreast sunfish include aquatic insects, small crustaceans, and fish. They most often feed in the middle of the water column. They are often associated with a particular haunt, such as a submerged tree, rock or overhanging bank. The abundance of snag habitats that provide a constant source of aquatic insects in a system is an important factor in regulating population health.
Redbreast sunfish are an important recreational species in South Carolina. According to creel census conducted in the Edisto and Combahee Rivers during 1987-91 by the South Carolina Department of Natural Resources, redbreast sunfish were the most popular fish among anglers during late spring and early summer, dominating harvests in terms of abundance. They are a forage fish for other predators such as largemouth bass. Predation by flathead catfish may have significant impacts on sunfish populations.
Allen, D.E. and C.S. Thomason. 1993. Survey and inventory of fisheries resources in the Combahee River. Study Completion Report F-32. SC Wildlife and Marine Resources Department, Columbia, SC.
Carlaner, C.D. 1977. Handbok of freshwater fishery biology. Vol. 2. Iowa State University, Ames, IA.
Fisheries Habitat Committee. 1995. Fishes of the Edisto River basin. SC Department of Natural Resources, Water Resources Division Report 6. Columbia, SC.
Jenkins, R.E. and N.M. Burkhead. 1994. Freshwater fishes of Virginia.
American Fisheries Society, Bethesda, MD.