Warmouth: Size, Predators, and Best Places to Catch Them

Written by Kaylee Keech
Published: October 5, 2023
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  • Color: Brownish-green with deep brown mottling and subtle purple hues. Dark barring down the length of the head and body. Whitish-yellow bellies. 
  • Lifespan: Unknown
  • Weight: rarely more than 2 pounds
  • Size (L): 3.9-7.1 inches
  • Prey: Waccamaw silverside, small crustaceans, aquatic insects, snails, crayfish, mussels, other small fish 
  • Group behavior: They sometimes live in small groups, especially when nesting. 
  • Fun fact: Male Warmouths are the ones that guard the nest of eggs. They are fiercely protective of their eggs and watch over them for a few days before they hatch. 
  • Estimated population size: Unknown, but presumed quite large.
  • Biggest threat: No known significant threats.
  • Most distinctive features: Bright red eyes, facial barring, males turn bright yellow during mating season. 
  • Other names: Warmouth bass, redeye, red-eyed bream, goggle-eye, mudgapper, stump knocker, mud bass, open mouth, Molly, mo-mouth, Morgan, weed bass, wood bass, rock Bass, strawberry “perch” 
  • Gestation period: 1-2 days
  • Predators: American alligator, little blue heron, wood stork, Anhinga, Florida green water snake, tricolored heron, double-crested cormorant, large fish like the largemouth bass, humans
  • Diet: Opportunistic carnivores
  • Common name: Warmouth
  • Number of species: one
  • Water type: freshwater 
  • Method of birth: Spawning — eggs 
  • Habitat: ponds, lakes, swamps, slow-moving streams, estuaries
  • Depth range
  • Used in cooking: rarely 
  • Conservation status: least concern 
  • Optimal pH: 7.0-7.5
  • Taxonomy:
    • Kingdom: Animalia 
    • Phylum: Chordata 
    • Class: Actinopterygii
    • Order: Perciformes
    • Family: Centrarchidae
    • Genus: Lepomis
    • Scientific Name: Lepomis gulosus

Warmouth Locations: 

  1. United States 
  2. Mexico 
  3. Puerto Rico 

Warmouth Summary

Bright red eyes and distinct vertical facial barring are the Warmouth fish’s most famous qualities. The fish are also known for their massive mouths, which allow them to eat a wide variety of foods. 

Their small size means they are not very popular for fishing. Still, they are abundant and easy to catch, so some fishermen make them into tasty meals. 

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Warmouth Facts

  • 1. Warmouths have giant mouths that they use to eat a wider variety of foods than any other sunfish.
  • 2. These fish are sedentary and secretive; they spend most of their time hiding and avoiding light. 
  • 3. Warmouths have bright facial markings that resemble the warpaint of some Native American tribes. This resemblance is possibly where the fish get their name. 
  • 4. These fish have a “least concern” conservation status because they are not popular for recreational or commercial fishing.
  • 5. Female Warmouths can lay between 4,500 and 63,200 eggs at once. 

Warmouth Classification and Scientific Name

The scientific name of the Warmouth is Lepomis gulosus. People most often call them Warmouths, but they also go by the longer title “Warmouth bass.” 

In some regions, locals have nicknames for the Warmouth. Some nicknames include weed bass, stumpkocker, jugmouth, and google-eye. 

The Warmouth is part of a class of vertebrates called Actinopterygii. Actinopterygii is the scientific term for ray-finned fishes. 

They are part of the family Centrarchidae, the sunfishes. Sunfish are territorial fish with broad, deep bodies with one spiny and one soft dorsal fin. 

They are part of the Genus Lepomis, a group known as the “true sunfishes.” There are 13 species in the Lepomis genus and 152 in the Centrarchidae family.  

The scientific name Lepomis gulosus comes from the Latin and Greek languages. “Lepomis” comes from a combination of the Greek word “lepis” and the Latin word “poma.” “Lepis” means “scaled,” and “poma” means “gill cover.” “Gulosus” is the Latin word for “large-mouthed.” 

The common name “Warmouth” comes from the fish’s massive mouth and large red eyes. 

Others speculate that the fish got their common name for their facial barring and red eyes. The markings resemble the warpaint that some Native Americans wore. 

Warmouth Appearance

These moderately sized fish have the typical long, flattened bodies and giant mouths of basses. Their round tails have a shallow fork at the center, and their pectoral fins are short and rounded. 

Warmouths have brownish-green bodies with deep brown mottling and subtle purple hues. There is dark, almost black, barring down the length of their heads and bodies. Their bellies are a creamy whitish-yellow. 

The most distinctive feature of the Warmouth fish is the large, flesh-like ear flaps. The ear flaps are black but have yellow edging and a tiny, deep red spot at the center. These appendages begin at the fish’s gill covers. Like the small spot on the ear flap, the eyes are bright red. 

Most of these fish grow to be 3.9-7.1 inches long and weigh about 2 pounds. 

The fish mature more quickly in crowded areas and don’t grow to their full length. It’s common for fish to stop growing between 3.9-4.7 inches in overpopulated areas. 

The biggest Warmouth on record weighed 2.4 pounds and was 8.3 inches long. Sources believe the fish may have been male but are unsure. 

Warmouth Distribution, Population, and Habitat

Warmouths live in the United States, Mexico, and Puerto Rico. 

Across the United States, Warmouths live in the Mississippi River Basin, the Great Lakes, and the Gulf of Mexico. They live as far west as Minnesota, southward to the Rio Grande in Texas, eastward to western Pennsylvania, and the Rappahannock River in Virginia. 

Sources are unsure how far the Warmouth’s native habitat spans. There are few early records of the fish. Plus, the US Fisheries Commission and state agencies introduced many fish to non-native water bodies across the country. 

Mexico, Puerto Rico, and 29 US states are non-native habitats of the Warmouth bass. 

Where Warmouths Live 

Warmouths are freshwater fish that live near the muddy bottoms of their favorite water bodies. They mostly live in calm water bodies, like ponds, lakes, and swamps, with lots of vegetation covering the bottom. They also reside in slow-moving creeks or streams. 

These fish are hardy and can handle a wide range of temperatures between 39-93°F. 

While Warmouths are typically freshwater fish, they can handle brackish waters. Most Warmouths live in waters with salinities of 1.5 PSU and below, but they can tolerate salinities up to 17 PSU. 

Warmouths that live in brackish waters usually live at the edges of blackwater, swampy estuaries. 

How Many Warmouths Are in the World 

The warmouth has a conservation status of “least concern” with a “stable” population trend. See a list of all conservation statuses here

The exact number of Warmouths in the world today is unknown. Researchers estimate that the population is quite large since the species is widely distributed across North America. 

Their population is stable, though their population is “severely fragmented.” There are many subpopulations across many locations. 

Where to Find Warmouths and How to Catch Them 

Fishermen rarely seek out Warmouths because they are small and don’t taste the greatest. They usually catch them by accident when trying for bluegills, bass, and other species. 

Still, some fishermen love fishing for Warmouths because they are plentiful. Warmouths are far easier to catch than bass and other species. 

Warmouths have large mouths made for eating a wide assortment of prey. They are opportunistic and won’t hesitate to snatch up a tasty morsel that comes their way. Lures and baits work incredibly well for catching Warmouths. Some of the fishermen’s favorite baits include worms, minnows, spinners, and flies. 

The best place to catch Warmouths is in the lowland waters of the southern United States, where the waters are warm. They are common in swamps, lakes, and slow-moving streams. 

Some experts suggest looking for a hollow cypress tree or stump in the fish’s habitat. There are likely several Warmouths hiding inside the hollowed-out tree. 

Warmouth Predators and Prey

These fish are opportunistic carnivores that eat various insects, crustaceans, and fish. 

What Eats Warmouths?

These moderately sized fish have several predators, including larger fish like largemouth bass. Even huge predators, like the American alligator, feast on Warmouths when available. 

Birds, like the little blue heron, wood stork, tricolored heron, Anhinga, and double-crested cormorant, frequently eat these fish. 

Humans are insignificant predators of Warmouths. The stunted growth common in these fish makes them less desirable for fishers than other species. 

Research doesn’t show any significant known threats to these fish. Sports fishing and using the fish for food may be a concern in some specific areas. Overall, humans don’t seem to be a big threat to the species. 

What do Warmouths Eat?

As juveniles, Warmouths mostly eat small crustaceans and aquatic insects. Adults can eat bigger foods, like larger aquatic insects, snails, mussels, small fish, and crayfish

Reproduction and Lifespan 

These fish reach sexual maturity between one and two years of age when they are about 3-3.9 inches long. 

Spawning occurs when the water is at least 70°F, usually in late spring through summer. Males turn bright yellow when they are ready to spawn. They also develop shimmering blue streaks across their gill covers and a bright orange spot on their dorsal fin.

Males prepare for spawning by digging a nesting site into the substrate at the bottom of their habitat. Their nesting site usually comprises several nests since the females will likely lay their eggs across many nests. 

These fish produce thousands of eggs each time they spawn. A single female can carry between 4,500 and 63,200 eggs at once. 

The males will fertilize the eggs after the female has laid them in their nest(s). 

The males guard the eggs for about five to six days and fiercely protect their nests. They typically guard the nests by themselves without the help of the mother. However, males often build their nests in groups so that many males simultaneously protect a similar area. 

The eggs begin hatching after about 25 to 48 hours when the water temperature is between 77-82.4°F. 

Researchers are unsure of how long Warmouth fish live for. 

Warmouth in Fishing and Cooking

Few recreational fishermen catch and cook Warmouth because they claim they don’t have the best taste. However, some fishermen claim that poor taste results from poor preparation. 

Warmouth lovers advise putting the fish on ice as soon as you catch them to keep them fresh and to get the best flavor. 

There don’t seem to be any recipes available specifically for cooking Warfish. Some fishermen recommend baking, broiling, French-frying, or pan-frying the fish. Preparing them with a batter is best to prevent them from drying out. 

People catch Warmouth fish by using bait and lures. They are easy fish to catch since they have giant mouths and are greedy opportunists. 

The best time to catch these fish is during dawn and dusk when they are most active and searching for food. The peak season for catching these fish is late spring through summer. 

FAQ

Where are Warmouth bass found?

Warmouths live in stagnant and slow-moving waters. Their favorite habitats include lakes, ponds, swamps, and slow-moving streams.

These fish live across the United States, Mexico, and Puerto Rico. They are native to some parts of the southern, northeastern, and central parts of the United States. 

Warmouths were introduced to 29 states where they were non-native. They are also non-native to Mexico and Puerto Rico but were introduced there. 

Is Warmouth a crappie?

Warmouths are not crappies. They are not a cross between a crappie and a bass, either, which is a common misconception. They are a species of sunfish unique to any other species of fish. 

Crappies are part of a completely different genus than Warmouths. They are part of the Lepomis genus, while crappies are part of the Pomoxis genus. 

Crappies are also far more popular for fishing and food. 

What is the difference between a Warmouth and a green sunfish? 

Warmouths and green sunfish are commonly confused with one another because they look very similar. 

Green sunfish are different than Warmouths because their bodies look more like a bass. Their bodies are more rectangular than the Warmouth’s. On the other hand, Warmouths have far larger mouths than green sunfish.

When it comes to color, green sunfish are more green and bright. Warmouths have some green in their scales, but their bodies consist of more muted browns. The Warmouths are also known for their brilliant red eyes, which green sunfish do not have. 

Green Sunfish 

Bluegill  

Redear Sunfish

The photo featured at the top of this post is © Clinton & Charles Robertson from RAF Lakenheath, UK & San Marcos, TX, USA & UK / CC BY-SA 2.0 – License / Original


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About the Author

I am a content writer who focuses on pets, wildlife, sustainability, and the environment. I specialize in blogs and love showing my readers how fascinating everything can be! I graduated from Millersville University with a Bachelor of Science in Biology with a Concentration in Marine Biology and a Bachelor of Arts in Science Writing. I volunteered at Raven Ridge Wildlife Center for five years, where I helped care for injured and orphaned Pennsylvania wildlife. I love all animals, wild and domestic. I've had all kinds of pets, including dogs, cats, birds, fish, a lizard, a snake, and a guinea pig. I may be curled up with a good book or my crochet when I'm not writing. I also enjoy exploring new places, especially by hiking or kayaking.

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