• Scientific Name: Micropterus salmoides
• Found in Illinois: Statewide
• State Average: 10"
• State Record: 13 lbs 1oz (Feb. 1976)
• Best Lures: plastic worms, jigs, spinnerbaits, crank baits, minnows, crayfish, night crawlers, worms.
• Top 3 Lakes (based on average size): Clinton, Springfield, Shelbyville
• Top 3 Rivers (based on average size): Mississippi, Ohio River Tributaries,Illinois

Habitat: 
The largemouth bass is the most widely distributed of the black basses and occurs throughout Illinois. The largemouth prefers shallow, weedy lakes and river backwaters — the same type of habitat that produces bluegills. Bass are also well adapted for life in small lakes or ponds. Largemouth are drawn to structures and will frequently be found under lily pads or lying in the shade of overhanging trees, piers or brush during the daytime. They will often move into shallow water in the evening and stay until after dawn for feeding, then retreat to deeper water or shade for the day. They are seldom found at depths greater than the deepest water in which rooted vegetation grows. Largemouth bass can tolerate quite high temperatures, although they will seek out deeper, cooler waters in the summer if possible.

Feeding and Habits: 
Largemouth bass are top predators in many lakes and are opportunistic feeders. They swallow their prey whole and will eat a wide variety of food. Largemouth bass mainly feed by sight, but they also use their lateral line, a sensory organ that runs along their body that can feel vibrations of swimming or distressed prey in the water. They typically search the weed beds and shallows for invertebrate and vertebrate foods, while keeping a vigilant eye on the surface for frogs, emerging mayfly or an unsuspecting dragonfly. Feeding drops off in late fall, and during the winter, bass are relatively inactive. The desire for warm water is shown by their spring migrations, seeking out the shallower littoral zones.

Reproduction: 
Largemouth bass in Illinois typically reach sexual maturity between ages 2–4 years, depending where they are in the state. When spring water temperatures start to reach 60ºF, males will begin to move inshore and select a nest site. Males build nests on a variety of substrate types and are most often in depths of 2–3 feet of water. Each nest is a small depression, roughly 2 feet in diameter, formed by the male using his caudal fin to clear the area of debris.

Male courtship begins by attracting a female and herding her over the nest to spawn. The female will tip her body to deposit a few egg while the male releases a small amount of sperm, fertilizing the eggs. A spawning pair can stay active for several hours, with females releasing 2,000 to 7,000 eggs per pound of body weight. The eggs fall into the nest and are sticky so they attach to the substrate in the nest. Once spawning has ended, the female leaves the area; the male is left to provide all of the parental care, which includes fanning the developing eggs to provide oxygen and enthusiastically defending the area to keep predators away.  Eggs usually hatch in 2–4 days and the larvae remain in the nest for about 5-10 more days (depending on temperature). When the fry become free swimming, they school above the nest with the male continuing his vigilant care.