Warmouth (Lepomis gulosus) - Introduced

18 cm warmouth.

Warmouths can be distinguished from other sunfishes by feeling for the patch of small teeth on the tongue.

Identification. Similar to rock bass and green sunfish. Body moderately deep. Very large mouth reaches beyond center of pupil in adults. Pectoral fins short and rounded. Opercular flap short with lighter (usually reddish or purplish) posterior edge. 3-5 dark, wavy streaks across cheek and opercle. Patch of small teeth present on the tongue. Anal spines 3. Usually brown to olive on back fading to yellowish-brown on belly. Lighter areas on sides often with iridescent, purplish cast. Back and sides with dark, irregular mottling. Dorsal, anal and tail fins mottled. Eyes reddish-brown. Body becomes yellowish and eyes turn bright red in spawning males. Juveniles with similar markings as adults.

Warmouth from Beacon Falls.

This 6-inch warmouth, caught by an angler through the ice during winter 2007-2008, was the first reported from Connecticut. Nick Gabris photo.

Size. Commonly 3 to 6 inches. Conn. max. observed size 7.1 inches. Max. reported size 12.2 inches.

Distribution. Native to the Eastern United States from Minnesota to western Pennsylvania and from eastern Texas to Florida. Have been introduced to a number of Central and Western states and north to areas in Maryland, New Jersey and New York. The only known occurrence in Connecticut is an apparently self-sustaining population in one small, private pond in Beacon Falls.

Warmouth distribution map.

All maps created in 2009. See CT DEEP Fish Community Data for updated distributions.

Habits. Solitary fish that prefer vegetated areas of swamps, ponds and slow-moving streams. Often found around stumps, fallen trees or similar structure. Can be readily taken on a variety of small lures and baits. Tolerant of poor water quality. Easy to keep in aquariums and can be trained to accept dried food pellets.

Comments. First reported in Connecticut by an angler in 2007. Mottled markings reminiscent of those found on some hybrid sunfish. However, it can be distinguished from other sunfish species by feeling for the raspy patch of teeth on the tongue. Will readily hybridize with other sunfishes in the Lepomis genus. Warmouths are not known to overpopulate waters where they are introduced and are thus not thought to be a threat to native fishes.


Text and images adapted from Jacobs, R. P., O'Donnell, E. B., and Connecticut DEEP. (2009). A Pictorial Guide to Freshwater Fishes of Connecticut. Hartford, CT. Available for purchase at the DEEP Store.