Plains Longear Sunfish, Lepomis aquilensis
Plains Longear Sunfish, Lepomis aquilensis. Fish caught from the Guadalupe River, Austin, Texas, June 2022. Length: 10.1 cm (4.0 inches). Catch, photograph and identification courtesy of Ben Cantrell, Sebastian, Florida.
Plains Longear Sunfish, Lepomis aquilensis. Fish caught from the Pecos River, New Mexico, August 2020. Length: 10.2 cm (4.0 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
Plains Longear Sunfish, Lepomis aquilensis. Fish caught from the Guadalupe River, Austin, Texas, June 2021. Length: 11.5 cm (4.5 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
Plains Longear Sunfish, Lepomis aquilensis. Fish caught from the San Antonio River, San Antonio, Texas, August 2018. Length: 13.6 cm (5.4 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
The Plains Longear Sunfish, Lepomis aquilensis, is a member of the Sunfish or Centrarchidae Family, and is known in Mexico as mojarra orejona. Globally, there are twenty species in the genus Lepomis, of which seven are found in the streams, rivers, lakes, and ponds of Mexico’s freshwater systems. Note: this species has historically been known as the Longear Sunfish. In 2021 the widely distributed Longear Sunfish was separated into seven separate species.
The Plains Longear Sunfish has a very deep and compressed body. They are very colorful, being olive to brown dorsally, transitioning to yellowish orange ventrally with blue-green bars on the sides of the head. They are dimorphic with breeding males being covered with numerous blue spots and wavy blue longitudinal lines on the head. Their pelvic fins and anal fins are brassy-orange. The gill cover has an elongated operculum flap with a white margin, giving rise to their common name. 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 is continuous with 10 to 12 spines and 10 to 12 rays; and, their pectoral fins are short and rounded with 13 or 14 rays. They have 10 to 14 gill rakers. They are covered with small scales.
The Plains Longear Sunfish is found in densely vegetated areas, both in shallow waters near the edges of lakes, ponds and in in slow moving large rivers and streams. They avoid strong current, turbid water, and silt bottoms. They reach a maximum of 24 cm (9.5 inches) in length and 0.8 kg (1 lb 11 oz) in weight. As of January 1, 2023, the International Game Fish Association world record stood at 0.79 kg (1 lb 12 oz), with the fish caught from Elephant Butte Lake, New Mexico in 1985. They prefer water temperatures above 10oC (50oF). They are opportunistic diurnal feeders that feed near the water surface consuming aquatic insects, insect larvae, crayfish, snails, other small invertebrates and small fish. In turn they are preyed upon by Largemouth Bass, Smallmouth Bass and Sunfishes as well as wading birds. They utilize vegetation for protection. Their spiny profile makes them difficult to swallow. Reproduction is oviparious and polygynandrous (promiscuous) and occurs continually when water temperatures are in excess of 23oC (73oF). During this period, males become highly territorial and aggressive, building very visible nests in shallow sand or gravel substrate, close together in colonies. Each female, based on size, will deposit between 200 and 4,000 eggs into the nest. Fertilization is external and males remain on the nest for 5 to 10 days until the eggs hatch and the young disperse. Young fish feed on plankton, but as they grow their diet shifts to aquatic insects and insect larvae. They have a life span of up to six years.
The Plains Longear Sunfish is a native to the freshwater systems of southern Texas and northern mainland Mexico within the States of Coahuila, Durango, Nuevo León, and Tamaulipas.
The Plains Longear Sunfish can be easily confused with the Pumpkinseed, Lepomis gibbosus (long pointed pectoral fins, no ear flap). They are separated from the six other newly introduced (formerly all Longear Sunfish) primarily by their geographic locations with only minor differences in their coloration patterns and body shapes observable.
From a conservation perspective the Plains Longear Sunfish is current considered to be of Least Concern with stable, widely distributed populations. Their long-term viability is threatened by human development that has destroyed native aquatic vegetation habitats, and has reduced the clarity of native streams. The Plains Longear Sunfish is not considered to be a quality food fish. They are however, considered to be an excellent game fish on light tackle and are a favorite of fly fishermen.