The redear sunfish generally resembles the Bluegil except for coloration and somewhat larger size. The redear sunfish also has faint vertical bars traveling downwards from its dorsal. It is dark-colored dorsally and yellow-green ventrally. The male has a cherry-red edge on its orer; females have orange coloration in this area. The adult fish are between 20 and 24 cm (7.9 and 9.4 in) in length. Max length is 43.2 cm (17.0 in), compared to a maximum of about 40 cm (16 in) for the bluegill. Lepomis microlophus averages at a size of about 0.45 kg (0.99 lb), also larger than the average bluegill.
Redear sunfish are native to North Carolina and Florida, west to south Illionois and south Missouri, and south to the Rio Grande drainage in Texas. However, this fish has also been widely introduced to other locations in the United States outside of its native range. In the wild, the redear sunfish inhabits warm, quiet waters of lakes, ponds, streams, and reservoirs. They prefer to be near logs and vegetation, and tend to congregate in groups around these features. This sunfish is also located in many marsh wetlands of freshwater.
The favorite food of this species is snails. These fish meander along lakebeds, seeking and cracking open snails and other shelled creatures. Redears have thick pharyngeal teeth (hard, movable plates in its throat) which allow it to crunch exoskeletons. It is even capable of opening small clams. The specialization of this species for the deep-water, mollusk-feeding niche allows it to be introduced to lakes without the risk of competition with fish that prefer shallower water or surface-feeding. In recent years, the stocking of redear has found new allies due to the fish's ability to eat quagga mussels, a prominent invasive species in many freshwater drainages.
During spawning, males congregate and create nests close together in colonies, and females visit to lay eggs. The redear sometimes hybridizes with other sunfish species redear sunfish is the first-known species of Centrarchidae based on fossil records, as old as 16.3 million years, dating back to the Mid Miocene period. Wikipedia