Redear Sunfish

Redear Sunfish, Lepomis microlophus

Redear Sunfish, Lepomis microlophus. Fish caught from within the Florida Everglades, May 2015. Length: 12 cm (4.7 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.

Redear Sunfish, Lepomis microlophus. Fish caught from an irrigation canal in the greater Micco, Florida area, November 2020. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.

Redear Sunfish, Lepomis microlophus. Fish caught from a lake in Carrollwood Park, Tampa, Florida, May 2013. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Ryan Crutchfield, Tampa, Florida.

The Redear Sunfish, Lepomis microlophus, is a member of the Sunfish or Centrarchidae Family, that is also known at the Shellcracker and in Mexico as mojarra oreja roja. Globally, there are thirteen species in the genus Lepomis, of which seven are found in the streams, rivers, lakes, and ponds of Mexico’s freshwater systems.

The Redear Sunfish has a very deep and compressed body. They are a dark olive brown dorsally transitioning gradually to almost white ventrally. The males have a distinctive relatively short ear flap which is black in color and has a white margin and a red spot at its tip; the females have a distinct orange edge on their opercle flap. The juveniles have light green and silver sides with dark spots and some have stripes. They often have small green specks on their heads and grey or black specks covering their bodies. They have a short head and a very small terminal mouth that does not reach the eyes. Their anal fin has 3 spines and 9 or 10 rays; their caudal fin is slightly forked with deep lobes; their dorsal fin has 10 to 12 spines and 10 to 12 rays; and, their pectoral fins have 13 or 14 rays and are long and pointed. They have short gill rakers. They are covered with small scales.

The Redear Sunfish is found in groups near the bottom in warm, quiet waters of lakes, ponds, streams, and reservoirs in close proximity to and in vegetation at depths greater than 2 m (7 feet). They reach a maximum of 43.2 cm (17 inches) in length and 2.61 kg (5 lbs 12 oz) in weight. As of January 1, 2024, the International Game Fish Association world record stood at 2.83 kg (6 lb 4 oz), with the fish caught from Lake Havasu, Arizona in May 2021. They are opportunistic bottom feeders. Their fry feed on algae and microcrustaceans. Their juveniles eat insects, insect larvae, and small snails. The adults are active at dawn and dusk (retreating during the day and night, feeding almost exclusively on snails but also consume small amounts of aquatic insects, copepods and crustaceans with hard shells. They are not nocturnal. In turn they are preyed upon by humans, Largemouth Bass, numerous Catfishes and wading birds. They retreat to shaded areas with deeper waters with vegetation for camouflage against predation, and rely on their cryptic colors and their spiny profile that makes them difficult to swallow. Reproduction is oviparous and polygynandrous (promiscuous) and occurs annually when water temperatures are in excess of 22oC (71oF). They are known to hybridize with other sunfish species. During this period, males become highly territorial and aggressive, building very visible nests in shallow gravel, sand or silt substrate, close together in colonies, and near vegetation. The males court females by snapping their jaws together to make a “popping” sound. Each female, based on size, will deposit between 9,000 and 80,000 eggs into the nest. Fertilization is external and males remain on the nest for 2 to 5 days until the eggs hatch and the young disperse. The juveniles remain close to aquatic plants for protection for up to 1 year. They have life spans of up to six years.

In Mexico they are found within the Rio Grande freshwater drainage system in the States of Chihuahua, Coahuila, Nuevo León and Tamaulipas.

The Redear Sunfish can be easily confused with the Pumpkinseed, Lepomis gibbosus (numerous wavy iridescent lines along the cheek and gill flaps). They are also similar to the Bluegill, Lepomis macrochirus (dark spot at the rear of dorsal fin), the Longear Sunfish, Lepomis megalotis, and the Redbreast Sunfish, Lepomis auratus, and both of which have elongated ear flaps, and the Spotted Sunfish, Lepomis punctatus (brilliant iridescent blue under the eyes).

From a conservation perspective the Redear Sunfish has not been formally evaluated, however their populations are ever increasing due to extensive human introductions into new areas. They have been stocked in some ponds to remove Quagga Mussels, Dreissena bugensis, a prominent invasive species. They are considered to be a quality food fish and also an excellent game fish on light tackle. They are considered to be the oldest living Sunfish dating to 16,300,000 years, the Middle Miocene.