The largemouth bass is a large, slender, elongated, streamlined sunfish with a very large mouth. The upper parts are greenish; the lower sides and belly are white, without dark spots or with spots that are irregularly arranged. The midside has a broad, dark, continuous stripe. The upper jaw reaches far beyond the rear margin of the eye, except in small young. The tongue is smooth. The dorsal fins are not well connected. The cheek scales are the same size as the rest of the body scales.
Total length: 10 to 20 inches; weight: ½ to 4½ pounds; maximum about 24 inches and 15 pounds.
Habitat and Conservation
Found in lowland lakes, artificial impoundments of all sizes, permanent pools of streams, and quiet backwaters of large rivers. The largemouth bass thrives in warm, moderately clear waters with little or no current. This species is most active at dawn and dusk. Its closest relatives are the smallmouth and spotted basses.
Carnivorous, feeding on fish, crayfish, large insects, and occasionally frogs, mice, snakes, or other small animals that fall into the water.
Popular game fish.
Individuals can live for 10 to 15 years. In Missouri, spawning occurs from mid-April through late May or June. They prefer to build their nests on rock or gravelly substrates, but any firm, silt-free bottom will do. Water depth over nests ranges from less than 1 foot to 15 feet or more. They do not nest where current or wave action are present. The eggs hatch in 3–4 days, and the fry rise and begin to feed 5–8 days after hatching. They form a tight school that stays over the nest another 4–5 days. Schools break up 26–31 days after hatching, when the young are slightly more than 1 inch long. The male largemouth is a more attentive parent than any of the other sunfishes. By the end of its first year, a largemouth can be more than 5 inches long.
Due to its widespread distribution and sporting qualities, the largemouth bass ranks as one of the most important North American warmwater sport fishes. Along with the crappies and white bass, it forms the backbone of the sport fishery in many large Missouri reservoirs and is almost invariably stocked as the principal predatory fish in farm ponds.
Because the largemouth bass is a top predator in aquatic habitats, its numbers definitely correlate with the abundance of its principal prey species, such as gizzard shad and other small fish, crayfish, and insects.