largemouth bass

Largemouth bass is a common native fish. Its native range is the United States and southern Canada east of the Great Plains. It has been intentionally introduced for sportfishing throughout the western U.S. as well as in Europe, Japan, South Korea, China, and South Africa.

Largemouth bass are found in a variety of habitats, including large and small lakes, reservoirs, ponds, rivers, and creeks. They prefer clear water with sandy bottoms and abundant vegetation. They are commonly found in areas with submerged logs and rocks.

Largemouth bass are opportunistic feeders, and they will consume any prey that will fit in their large mouths. The typical lifespan in the wild is 15 to 23 years.

The size of an adult fish depends on its age, food availability, water temperature, and other environmental factors. Largemouth bass are typically 2″ to 8″ (5 to 20 cm) in total length after one year, 2¾″ to 12½″ (7 to 32 cm) long after two years, 6″ to 14½″ (15 to 37 cm) long after three years, and 8″ to 16″ (20 to 41 cm) long after four years. However, they live longer and they can get much larger. The record largemouth bass caught in Minnesota weighed 8 pounds 15 ounces, was 23″ in length, and was caught in Auburn Lake in Carver County in 2005. There is currently no state catch and release record for largemouth bass.

The mouth is large. The upper jaw extends back past the eye in fish longer than 4″ (10 cm). The eyes are golden brown. There are 9 to 12 rows of scales on the cheeks. They are about the same size as the scales on the bony flap that protects the gills (operculum).

The body is elongated and thick. It is stocky, slightly laterally compressed, and oval in cross section. The body color is olive gray to shiny green on the back and the upper sides, and silvery green to yellowish green on the lower sides, with a heavy black stripe on each side separating the two areas. The lower sides may be speckled, but they do not have rows of small spots. The black stripe is prominent on young fish, but it fades, typically breaking up into a series of blotches, as the fish reaches maturity. The belly is white or cream colored.

The dorsal fin is deeply divided. The front portion has 9 spines and is only slightly rounded. It is almost separated from the softer rear portion, which has 12 to 14 rays. The anal fin has 3 spines and 11 to 12 rays. The pectoral fins have 13 to 17 rays. The row of pores that runs from the gills to the tail (lateral line) has 58 to 72 scales.

Typical total length

1 year old: 2″ to 8″ (5 to 20 cm)

2 year old: 2¾″ to 12½″ (7 to 32 cm)

3 year old: 6″ to 14½″ (15 to 37 cm)

4 year old: 8″ to 16″ (20 to 41 cm)

Large and small lakes, reservoirs, ponds, rivers, and creeks

15 to 23 years

Any prey that will fit in its mouth.

Sources

4, 6, 7, 24, 29, 30, 76.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu, 6/30/2025).

Nonindigenous Aquatic Species (NAS) information resource for the United States Geological Survey

Mundahl, N.D. 1994. Distribution of fish species within ten watersheds in southeastern Minnesota. Final report submitted to the Minnesota Department of Natural Resources. Unpaged.

Common

Genus
This species was formerly classified as Micropterus salmoides. A recent phylogenetic analysis (Kim et al. 2022) concluded that the name Micropterus salmoides is the valid name for the Florida Bass, whose range is restricted to the southeast. The authors proposed renaming the widespread species Micropterus nigricans, the oldest name available.

Higher level taxonomy
The taxonomy of fishes above the rank of order is in flux, and it seems that no two sources agree. ITIS does not agree with Catalogue of Life, and neither agree with iNaturalist. Wikipedia is inconsistent – it does not even agree with itself. MinnesotaSeasons will follow the ranking of Catalogue of Life for the higher level (supraordinal) taxonomy.

Green Bass on the green fly
Fish’n Cam

Largemouth Bass (Micropterus salmoides)
Vertebrate Zoology Fall 2020

Gregory Gilman
6/19/2025

Location: Rochester, MN

Caught and released this am