The genus Micropterus includes some of the well-known freshwater game fishes including the small- and largemouth basses. The latter belong to the sunfish family (Centrarchidae) and should not be confused with either the temperate basses of the family Percichthyidae, which includes the striped and white basses, or the sea basses and groupers of the family Serranidae. They are the largest members of the sunfish family, often reaching a weight of 2-4 kg (5-8 lbs), and the South Carolina record is currently over 7 kg (16 lbs). Large and smallmouth bass can be distinguished from other sunfish in the family Centrarchidae by their rather elongate body and olive coloration. As with all sunfish, largemouth bass have a spinous first dorsal fin followed by a soft-rayed second dorsal. Coloration depends on water clarity, but generally their color is olivaceous, green dorsally fading to a pale underside with a distinct black stripe running from the fish's opercular flap to the base of the tail. The corner of the mouth extends past the eye (thus the name "large mouth"), and no teeth are present on the fish's tongue. The fish has a moderately elongate and slightly compressed body. They usually have 12 dorsal rays and 3 anal spines.
Habitat and Biology
The native range of largemouth bass is from the lower Great Lakes to the Mississippi River drainage, the Gulf Coast, and Florida. Along the Atlantic coast, the species occupies rivers and ponds as far north as Virginia. Bass are generally confined to fresh water, but they may move into low salinity areas of tidal rivers for short periods of time. They prefer very slow-moving water, especially lakes and larger streams or rivers, inshore waters of ponds, lakes, reservoirs, sloughs of the Delta, creeks, and some irrigation ditches. Largemouth bass are often found around or near submerged structures such as a fallen trees, stumps, rocks, grasses, or an overhanging bank.
The largemouth bass is native to the ACE Basin. In the ACE Basin the largemouth bass is commonly found in the riverine ecosystem, a freshwater community. They prefer slow-moving water and are found throughout the area from small creeks to the low salinity areas of the estuary. They are often stocked in private impoundments as a predatory species. They commonly lurk near cover during the day and move into shallow areas to feed at dark.
Largemouth bass found in the ACE Basin appear to be closely linked genetically to the Florida subspecies. Sexual maturity occurs in the second year. Spawning occurs in the spring from late April to June when water temperatures near 65o F. Spawning occurs over a nest constructed along the shallow margins of their habitat. Male fish clear a shallow, circular depression in a gravelly or sandy bottom of a deep pool and establish a territory. Several females spawn in the nest of a single male. The female deposits up to 1 million eggs that are fertilized by the male as they are deposited in the nest. The male then devotes full time to guarding the nest from predators and fans the eggs to increase oxygen levels and reduce siltation on the nest. While guarding the nest and the young, he does not feed. When the fry hatch they form a school and stay around the nest for several days. The attentive male continues to protect the fry for some time after they leave the nest.
Young bass feed on zooplankton, insects, and small fishes and are also sometimes cannibalistic. They grow up to 20 cm (8 in) in the first year. Adults are top level carnivores in their respective habitats, feeding primarily on crawfish and many fish species, as well as on snakes, frogs, and even baby ducks. Feeding activity takes place during both day and night and is initiated by both hunger and reflex. Largemouth bass are sight feeders and actively hunt for food. This genetic reflex is behind the success of many of the fishing lures used to capture them. The average maximum life span of largemouth bass is typically 10 to 12 years.
Along with trout, largemouth bass are the most sought after game fish in the United States. The world record largemouth was 10 kg (22.25 lbs.) captured in Montgomery Lake, Georgia. In South Carolina, fishing for largemouth bass occurs in lakes and creeks in riverine ecosystems.
Chew. R.L. 1968. Annual progress report for investigations project: Largemouth bass study. State of Florida Game and Freshwater Fish Commission, Tallahassee, FL.
Thomason, C.S., D.E. Allen, and J.S. Crane. 1993. A fisheries study of the Edisto River, SC. Wildlife and Marine Resource Department, Study Completion Report, Federal Aid Projects F-32 and F-30.
Wisconsin Conservation Department. 1961. The largemouth bass: Its life history, ecology, and management. Publication 232-67. Madison, WI.