Lepomis microlophus

Redear sunfish

Family: Centrarchidae · Class: Actinopterygii · Order: Perciformes

The redear sunfish is a medium-sized freshwater fish native to the southeastern United States but widely introduced throughout North America, including California. Adults typically measure 15 to 25 centimeters (6 to 10 inches) in length, with larger specimens occasionally reaching 30 centimeters (12 inches). The body is laterally compressed and oval-shaped, characteristic of the sunfish family. The species is distinguished by a distinctive red or orange margin on the black opercular flap, which gives the fish its common name. The body coloration ranges from olive-green to bluish-green on the dorsal surface, fading to lighter green or yellow on the sides, with a whitish belly. Males develop more vibrant coloration during breeding season, with enhanced yellow and orange hues. Redear sunfish are not native to California but have been widely introduced throughout the state's warm-water habitats. According to the California Department of Fish and Wildlife, the species was first introduced in the 1940s and has since established populations in numerous reservoirs, lakes, and slow-moving rivers across California. The species is now found from the Central Valley to Southern California, including major water bodies such as Lake Almanor, Clear Lake, and various reservoirs in the Colorado River system. The distribution continues to expand through both intentional stocking and natural dispersal. The species inhabits warm, shallow waters with abundant aquatic vegetation and soft substrates. Redear sunfish prefer lakes, ponds, and slow-moving streams with water temperatures ranging from 18 to 30 degrees Celsius (64 to 86 degrees Fahrenheit). They typically occupy depths of 1 to 6 meters (3 to 20 feet) but may venture deeper during winter months. The species thrives in eutrophic waters with high productivity and shows tolerance for varying water chemistry conditions. Redear sunfish are primarily molluscivores, feeding extensively on snails, clams, and other mollusks using specialized pharyngeal teeth adapted for crushing shells. This dietary preference distinguishes them from other sunfish species and reduces competition with native fishes. The diet also includes aquatic insects, crustaceans, and small fish. Spawning occurs from March through August when water temperatures reach 18 degrees Celsius (64 degrees Fahrenheit). Males construct circular nests in sandy or gravelly substrates in shallow water, typically 0.5 to 2 meters (1.6 to 6.6 feet) deep. Females deposit 2,000 to 40,000 eggs depending on size, with males providing parental care by guarding the nest and fanning eggs until hatching occurs in 3 to 5 days. Redear sunfish have no federal or state conservation listing status in California, as they are a non-native species. However, their introduction has raised ecological concerns regarding impacts on native fish communities and aquatic ecosystems. The species' specialized mollusk-feeding behavior can significantly reduce native freshwater mollusk populations, potentially affecting ecosystem dynamics. Management efforts focus on preventing further introductions rather than conservation of existing populations.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.