Smallmouth Bass

Quick Facts

Species type

Nonnative

Size

8 to 22 inches in length

Habitat

Cool, clear streams with abundant shade and cover, moderate currents and gravel or rubble substrate; also found in large, clear lakes and reservoirs

Range

Native range extends from the Great Lakes south to northern Georgia and Alabama, east to the Appalachian range and west to eastern Oklahoma. It was widely introduced in the northeastern United States, and common in Bay tributaries north of the Rappahannock River; rare to occasional south of the Rappahannock River; absent from Eastern Shore rivers and streams.

Diet

Insects, amphibians, fish and crayfish, as well as the young of other smallmouth bass

Lifespan

Up to 7 years

Conservation status

Stable

Appearance

Adult smallmouth bass can grow up to 26 inches long, but most are 8 to 22 inches. Their elongate body is pale brown or olive green, while their belly is yellow-white in color. The fish's body features a number of small, dusky brown blotches and sometimes five to 15 indistinct dusky lateral bars. Unlike the largemouth bass, the lower jaw of its moderate-sized mouth does not extend past its eye.

Feeding

Juveniles consume zooplankton, insect larvae, small fish and crayfish. Adults feed on insects, amphibians, fish and crayfish, as well as the young of other smallmouth bass.

Predators

Predators include other fish, turtles and birds like ospreys and kingfishers.

Reproduction and life cycle

Spawning occurs on rocky lake shoals or in river shallows from spring to early summer when water temperatures reach 55 to 70 degrees Fahrenheit. Males build and guard small, round nests. When a female enters a male’s territory, a complex mating dance occurs, with the pair rubbing and biting each other.

Several females may spawn in the nest of one male, and individual females may spawn in the nests of several males. Eggs hatch in four to six days, and young remain in and around the nest for the first two weeks of their lives. The oldest known age of the smallmouth bass is 18 years, but individuals older than 7 are uncommon.

Did you know?

An important sport fish, the record smallmouth bass was caught in Kentucky, measured 2.3 feet and weighed 11.9 pounds.

Sources and additional information

Life in the Chesapeake Bay by Alice Jane Lippson and Robert L. Lippson
Fishes of Chesapeake Bay by Edward O. Murdy, Ray S. Birdsong and John A. Musick
Micropterus dolomieu: Bass – University of Michigan Museum of Zoology
Smallmouth Bass – Maryland Department of Natural Resources

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