The warmouth (Lepomis gulosus) is a freshwater fish of the sunfish family (Centrarchidae) that is found throughout the eastern United States. Other local names include molly, redeye, goggle-eye, red-eyed bream, and strawberry perch.
Description
thumb|Adult warmouth from Kickapoo State Park, Illinois
thumb|A juvenile specimen of Lepomis gulosus from Kickapoo State Park, east-central Illinois
Adult warmouth appear dusky, with a mottled brown, somewhat purplish coloration. The ventral surfaces are yellow, with a red dot present on the otherwise black opercular flaps, outlined in yellow. It most commonly has three spines in the anal fin and 6 to 13 spines in the dorsal fin, These fish are typically long, but can grow to over in length, and reach . a black spot near the base of the dorsal and anal fins, The warmouth is a highly aggressive and hardy fish, and they can live in ponds, lakes, rivers, and backwater streams and can often survive in streams with low oxygen levels where other species of sunfish cannot. The species exists with breeding populations in southern portions of Canada, and likely has existed there for many years prior to being detected.
Ecology
The primary diet of the warmouth consists of insects, crayfish, and other fish. The primary diet of young warmouth is microcrustaceans and aquatic insect larvae, whereas larger specimens tend to mainly consume crayfish, freshwater shrimp, isopods, Their predators include larger fish, snakes, turtles, alligators, and birds. The primary habitats the warmouth occupies are areas with ample vegetation as cover with slower-moving water, often around stumps, brush piles, and other dense entanglements that allow the warmouth the ability to ambush prey, yet escape larger predators that may threaten them. Their spawning often begins in May and lasts until July. Nests are primarily constructed on rock or gravel substrates, usually located in or near to some type of structure in the water column. Unlike most other Lepomis species, the warmouth does not nest in a colony unless ideal nesting habitat is limited. When in breeding condition, the males' eyes turn red. After the female lays her eggs, the male fertilizes the eggs and aggressively defends the nest, eggs and fry from any intruder-including other females. Males are most commonly found defending the nest for up to five days later until the fry have hatched.
The warmouth is an extremely adaptable species that can survive in many different conditions, in many river systems east of the Rocky Mountains. Often, the warmouth prefers habitats where there is slower-moving water. The most common cause of concern for the warmouth is hybridization with other Lepomis spp. that often inhabit the same areas as the warmouth. The species known to hybridize with it are the green sunfish (L. cyanellus) and the bluegill (L. macrochirus), as well as the largemouth bass (Micropterus salmoides) and the black crappie (Pomoxis nigromaculatus). This does not seem to affect the overall health or longevity of the species.
Since warmouths are not migratory fish, their populations should be relatively easily monitored throughout much of their existing ranges. According to Warren,
References
- http://www.bio.utk.edu/hulseylab/Fishlist.html
Texas Parks and Wildlife Department, http://www.tpwd.state.tx.us/huntwild/wild/species/war/