The largemouth bass (Micropterus nigricans) is a carnivorous, freshwater, ray-finned fish in the Centrarchidae (sunfish) family, native to the eastern and central United States, southeastern Canada and northern Mexico.

[7] It is the largest species of the black bass, with a maximum recorded length of 29.5 inches (75 cm) and an unofficial weight of 25 pounds 1 ounce (11.4 kg).

The largemouth bass was first formally described as Labrus salmoides in 1802 by the French naturalist Bernard Germain de Lacépède with the type locality given as the Carolinas.

[14] The largemouth bass is an olive-green to greenish gray fish, marked by a series of dark, sometimes black, blotches forming a jagged horizontal stripe along each flank.

Largemouth bass prefer habitats with abundant littoral vegetation and generally maintain relatively small home ranges in lakes.

[20] Adults consume smaller fish (bluegill, banded killifish, minnows, juvenile bass), shad, worms, snails, crawfish, frogs, snakes, and salamanders.

[citation needed] In larger lakes and reservoirs, adult bass occupy slightly deeper water than younger fish, and shift to a diet consisting almost entirely of smaller fish like shad, yellow perch, ciscoes, suckers, shiners, other cyprinids, freshwater silversides, and sunfish (such as bluegill and green sunfish).

Under overhead cover, such as overhanging banks, brush, or submerged structure, such as weedbeds, points, humps, ridges, and drop-offs, the largemouth bass uses its senses of hearing, sight, vibration, and smell to attack and seize its prey.

Adult largemouth are generally apex predators within their habitat, but they are preyed upon by many animals while young, including great blue herons, larger bass, northern pike, walleye, muskellunge, yellow perch, channel catfish, northern water snakes, crappie, common carp, and American eels.

[22] Notably in the Great Lakes Region, Micropterus salmoides along with many other species of native fish have been known to prey upon the invasive round goby (Neogobius melanostomus).

Finally, depending on the water temperature, the male will stay with the nest until the infant bass are ready to swim out on their own, which can be about two more weeks after they hatch.

[27] Largemouth bass are keenly sought after by anglers and are noted for the excitement of their 'fight', meaning how vigorously the fish resists being hauled into the boat or onto shore after being hooked.

Large golden shiners are a popular live bait used to catch trophy bass, especially when they are sluggish in the heat of summer or in the cold of winter.

[35] In 2011, researchers found that in streams and rivers in the Iberian Peninsula, juvenile largemouth bass were able to demonstrate trophic plasticity, meaning that they were able to adjust their feeding habits to obtain the necessary amount of energy needed to survive.

[39] The largemouth bass in Freshwater Protected Areas also had a higher aerobic scope, potentially providing them with more energy for growth, reproduction, and responding to environmental change.

[39] Another study found that maternal exposure to the stress hormone cortisol resulted in a lower responsiveness to angling stressors in their progeny.

[40] These studies in tandem provide evidence that repeated exposure to stress hormones and high angling pressure can bring out suboptimal phenotypes in largemouth bass populations.