Largemouth bass
Micropterus salmoides (Lacepede, 1820)

member of the Sunfish Family (Centrarchidae)

photos by Konrad P. Schmidt












What's In a Name?
Largemouth bass: from the size of mouth, compared to the smallmouth bass.

Micropterus (My-crop´-ter-us) means "small or short fin" in Greek; a reference to the damaged fin in the original specimen
salmoides (sal-moid´-ees) means "trout-like" in Latin


    Where Do They Live?
Largemouth bass occur in all of the major drainages of Minnesota, but are most common in the central to north-central portions of the state. Here they commonly inhabit small to medium-sized clear lakes that have warm waters, sandy shorelines, and numerous weed beds. They also live in some of the muddy lakes of southern Minnesota and in the backwaters of the Mississippi and St. Croix rivers. Largemouth bass are commonly found with bluegill, crappies, northern pike, yellow perch, brown bullhead, and many kinds of minnows.


How Big Do They Get?
How Long Do They Live?
The spunky largemouth bass grows fairly fast, reaching 250-330 mm (10-13 in) and 0.9-1.4 kg (2-3 lbs) in 3 to 4 years. True largemouth anglers will tell you there are plenty of 2.3-kg (5-lb) fish in our lakes, but rarely does one end up in the boat. The state record is 4.6 kg (10 lbs 2 oz). A largemouth bass can live up to 15 years, but fish over 10 years old are rare.


What Do They Eat?
Largemouth bass are carnivores (animal eaters). As larvae, they eat copepods and waterfleas but soon add seedclams (ostracods) and small insect larvae. Before the end of their first growing season, they add small fishes to their diet. Largemouth consume many species of fishes (including sunfishes, yellow perch, and minnows), crayfish, surface insects, and frogs.

"Cool Fact": It takes about 1.8 kg (4 lbs) of food to produce every 0.5-kg (1 lb) of largemouth bass


What Eats Them?
Larval and small juvenile largemouth bass are eaten by yellow perch and young walleye. Juveniles are eaten by northern pike and musky. Because of their size, swimming speed, and dorsal (back) spines, adult largemouth bass probably escape most predators' attempts. Instead, they succumb to the hook of the patient angler.


How Do They Reproduce?
Largemouth bass spawn mostly in May and June in Minnesota when water temperature goes above 15.5° C (about 60° F). As in other sunfish species, the male prepares the nest. He usually picks a site in shallow water (0.25-1.5 m or 1-4 ft deep) in areas of bulrushes, water lilies, coontail, or other submerged plants. The bottom may be gravel, sand, or even mud. The very assertive, territorial male uses his fins to clear an area 0.6-1 m (about 2-3 ft) in diameter until he exposes gravel, shells, or plant roots. When a female approaches the nest, the male may rush toward her and attempt to push her into the nest. If she enters the nest and turns on her side, the male moves next to her and they release eggs and sperm. This may be repeated several times. A single female may lay 2,000-40,000 eggs depending on her size. Both males and females spawn with multiple partners. The male fans the eggs (embryos actually) and protects them from predation.

The eggs (embryos) usually hatch in about a week. They spend another week in the nest while they develop their mouths, digestive tracts, and some fin rays. Finally, they swim up into the water column and begin feeding. At this time, most larvae of the sunfish family swim away. But largemouth larvae continue to swim together in a "brood swarm" for the next 3-4 weeks as they develop into juveniles. The male largemouth continues to protect this swarm until it breaks up.


Conservation and Management
Largemouth bass is one of the top 3 warm-water sportfish in Minnesota. This species sometimes is planted in ponds or small lakes to get a population going. The usual management strategy for most populations is to protect bass from angling during at least part of the spawning season and limit the number of bass that can be taken daily.




Permission is granted for the non-commercial educational or scientific use of the text and images on this Web document. Please credit the author or authors listed below.

Photographs by Konrad P. Schmidt
Text by Nicole Paulson & Jay T. Hatch in cooperation with
the Minnesota Department of Natural Resources' MinnAqua Aquatic Program

This page developed with funds from the
MinnAqua Program
(Minnesota Department of Natural Resources, Division of Fisheries)
and the
Sport Fish Restoration Program (Fish and Wildlife Service, US Department of the Interior)

Maintained by Jay T. Hatch
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul

Last updated 04 February 2002