Redear sunfish exhibit stable population trends throughout its range and are in no danger of decline.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Redear sunfish have several predators, including humans (Homo sapiens). They are considered a sport-fish species and are stocked in many lakes and streams. Humans commonly consume them and their larvae are prey to many other sport-fish species, including largemouth bass (Micropterus salmoides) and catfish (Genus: Ictalurus). Redear sunfish avoid predation by retreating to shaded areas and deeper waters. Redear sunfish carcasses are often scavenged by birds and raccoons (Procyon lotor).
Known Predators:
Anti-predator Adaptations: cryptic
Redear sunfish have laterally compressed bodies that are green, grey, or black. They can be distinguished from other sunfish via 3 different characteristics: 1) the red or orange margin on the opercular flap, 2) cheeks without conspicuous orange and blue streaks, and 3) pectoral fins that are greater than a third of the length typically found in sunfish. They often have small green specks on their heads and grey or black specks covering their bodies. Their pectoral fins have 13 to 14 pectoral rays, which taper to a terminal point. Their dorsal fin has 10 to 11 spines, and the anal fin has 3 spines. The terminal end of the opercular flap is marked by a large black spot, accompanied by two smaller white spots. The brightly colored terminal margin on the opercular flap is red in males and orange in females. At sexual maturity they are approximately 224 mm and can weigh as much as 454 g.
Redear sunfish are similar in appearance to their close relative, pumpkinseed sunfish (Lepomis gibbosus). As a result, the two species are often confused for one another. However, pumpkinseed sunfish have a number of wavy iridescent lines along the check and opercular flap that are not present in redear sunfish.
Range mass: 1.3 (high) kg.
Range length: 35.5 (high) cm.
Average length: 22.4 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently
Redear sunfish have an average lifespan of 6 years. The oldest wild-caught redear sunfish was 8 years old at time of capture. In captivity they can live to be 7 years old.
Range lifespan
Status: wild: 8 (high) years.
Range lifespan
Status: captivity: 7 (high) years.
Average lifespan
Status: wild: 6 years.
Redear sunfish prefer warm and calm or stagnant waters. As a result, preferred habitat is restricted to ponds, lakes, river backwaters, and reservoirs. The riverine habitats in which they are found, tend to be large and slow flowing with moderate amounts of aquatic vegetation. Redear sunfish are mainly found in water that is at least 2 m deep. They commonly live in low salinity waters (less than 4 ppt) but have been found in waters with salinities as high as 12 ppt.
Average depth: 2 m.
Habitat Regions: temperate ; tropical ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams
Wetlands: marsh
Redear sunfish are native to the central and southern United States and can be found in the St. Lawrence-Great Lakes and Mississippi River drainages, as well as the Atlantic and Gulf Slope drainages. Redear sunfish have been introduced as game fish throughout the United States, as well as in Morocco, South Africa, Panama, and Puerto Rico.
Biogeographic Regions: nearctic (Introduced , Native ); palearctic (Introduced ); ethiopian (Introduced ); neotropical (Introduced )
Redear sunfish are mainly bottom feeders. Fry stay in benthic waters and feed on algae and microcrustaceans. Juveniles eat insects, insect larvae, and small snails. Once their jaws fully develop, usually at about 1 year old, they begin to feed exclusively on snails. Adults feed on snails, aquatic insects, copepods, and organisms with hard shells, such as crustaceans. Evidence suggests that redear sunfish prefer snails with moderate shell thickness, as opposed to thin or thick shelled snails.
Animal Foods: insects; mollusks; aquatic or marine worms; aquatic crustaceans; zooplankton
Plant Foods: algae
Primary Diet: carnivore (Molluscivore )
Introduced redear sunfish have significantly impacted native fish populations. For example, when introduced into habitats occupied by pumpkinseed sunfish (Lepomis gibbosus), pumpkinseed populations significantly declined. Redear sunfish have strong jaws, which allow them to crack mollusk shells more easily than pumpkinseed sunfish can. As a result, redear sunfish likely decrease food availability for pumpkinseeds.
Redear sunfish are host to the non-native parasitic copepod, Neoergasilus japonicus. Neoergasilus japonicus attaches to the outer surface of its host, likely feeding on the dermal tissue underlying the scales. Gut content analysis, however, shows that the primary diet of free-swimming N. japonicus consists primarily of blue-green algae.
Commensal/Parasitic Species:
Redear sunfish are considered a sport fish and are regularly consumed throughout United States.
Positive Impacts: food
There are no known adverse effects of redear sunfish on humans. However, when redear sunfish populations are introduced to non-native waters, they may negatively affect the ecosystem and out-compete native fish species. This may affect the fishing industry and overall health of ecosystems that humans depend on for food and water.
Optimal incubation temperatures for redear sunfish eggs range from 22°C to 24°C. Incubation normally lasts 50 hours. After hatching, fry hide in gravel nests until about 3 days after hatching. Juveniles stay close to aquatic plants for protection and at 1 year old, leave the protective cover of aquatic plants to prey on open-water snails.
Growth rates appear to be dependent on turbidity as redear sunfish grow more rapidly in less turbid water. Different age classes can be identified according to size. First year fish range from 50 to 100 mm in total length (TL), and second year fish range from 110 to 140 mm TL. Fish that are 5 to 6 years old range from 200 to 250 mm TL.
Development - Life Cycle: indeterminate growth
Redear sunfish use several modes of communication. It has been suggested that Lepomis species use chemical cues during nest building. During spawning, redear sunfish swim in a circular pattern around their mates. Males produce a popping sound to induce egg laying in females, which they produce by clapping the jaws shut. Finally, females select mates, at least in part, based on the pattern and intensity of a potential mate's coloration.
Communication Channels: visual ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
During mating season, male redear sunfish make popping sounds while in close proximity to females, which are used to gain the attention of potential mates. During courtship, males repeatedly surge toward potential mates while making popping sounds, which are made by clapping the jaws shut. Males also gain the attention of females via chemical and visual cues.
Male redear sunfish construct nests made from sand, gravel, and mud. Nests are typically found near aquatic plants, which provide cover for juveniles prior to maturation. Nests are approximately 25 to 61 cm wide and occur anywhere from 1 to 6 m deep. After fertilization, males do not leave the nest until all their eggs have hatched. Female sunfish lay their eggs in several nests each mating period.
Mating System: polyandrous
Redear sunfish mate once per year. The start of spawning season depends on water temperature, with warmer temperatures resulting in earlier spawning. Spawning typically occurs in shallow water at temperatures between 21°C and 24°C. Spawning begins in early spring and ends in mid-summer but may extend into early October in warmer climates. Maturation rates are also dependent on climate, as individuals start to spawn at 1 year old in warmer climates and at 2 years old in colder climates. Finally, female sunfish produce between 9,000 and 80,000 eggs per mating season.
Breeding interval: Redear sunfish breed once yearly.
Breeding season: Redear sunfish breed from early spring to mid-summer.
Range number of offspring: 9000 to 80000.
Average gestation period: 50 hours.
Average time to independence: 3 days.
Range age at sexual or reproductive maturity (female): 1 to 2 years.
Range age at sexual or reproductive maturity (male): 1 to 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (External ); oviparous
Male redear sunfish build nests prior to spawning and protect their nest for up to 3 days after spawning.
Parental Investment: male parental care ; pre-fertilization (Protecting: Male); pre-hatching/birth (Protecting: Male); pre-weaning/fledging (Protecting: Male); pre-independence (Protecting: Male)
The redear sunfish (Lepomis microlophus), also known as the shellcracker, Georgia bream, cherry gill, chinquapin, improved bream, rouge ear sunfish and sun perch) is a freshwater fish in the family Centrarchidae and is native to the southeastern United States. Since it is a popular sport fish, it has been introduced to bodies of water all over North America. It is known for its diet of mollusks and snails.
The redear sunfish generally resembles the bluegill except for coloration and somewhat larger size. The redear sunfish also has faint vertical bars traveling downwards from its dorsal.[3] It is dark-colored dorsally and yellow-green ventrally. The male has a cherry-red edge on its operculum; 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. Redear sunfish on average reach about 0.45 kg (0.99 lb), also larger than the average bluegill.[4]
Redear sunfish are native to the Southeast U.S. They range from North Carolina to Florida, west to southern Illinois and Missouri, and south to the Rio Grande drainage in Texas.[5] 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 freshwater marsh wetlands.
The favorite food of this species is snails, which it obtains by cracking their shells, hence this feisty gamefish's common name: shellcracker. These fish meander along lakebeds, seeking and cracking open snails and other shelled creatures. VanderKooy et al. (2000) observed that large L. microlophus predominantly focus on hard-shelled prey such as ostracods, hydrobiid snails and mussels throughout the entire year. In the same field investigation, it was observed that smaller fish tended to also consume zooplankton, amphipods, chironomid and ceratopongonid larvae and cladocerans, with varied distributions depending on the season.[6] They are also believed to feed on algae, aquatic worms,[7] copepoda,[8] midge larvae, ephemeropteran and odonata nymphs, crayfish, small fish, and fish eggs.[9][10] 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.[11]
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.[12]
The redear sunfish is the first-known species of Centrarchidae based on fossil records, as old as 16.3 million years, dating back to the Middle Miocene.[13]
Redear sunfish is a popular panfish among recreational anglers. The IGFA all-tackle world record for the species stands at 2.61 kg (5 lb 12 oz) caught in 2014 from Lake Havasu in Arizona.[14]
The redear sunfish (Lepomis microlophus), also known as the shellcracker, Georgia bream, cherry gill, chinquapin, improved bream, rouge ear sunfish and sun perch) is a freshwater fish in the family Centrarchidae and is native to the southeastern United States. Since it is a popular sport fish, it has been introduced to bodies of water all over North America. It is known for its diet of mollusks and snails.
Large shellcracker before preparation for consumption
