The smallmouth bass is generally green with dark vertical bands rather than a horizontal band along the side. There are 13-15 soft rays in the dorsal fin, and the upper jaw never extends beyond the eye. Micropterus is Greek meaning "small fin" [see Guadalupe bass for further explanation]. The species epithet dolomieu refers to the French mineralogist M. Dolomieu.
Because of its reputation in other parts of the US as an excellent sport fish, the smallmouth bass has been introduced into a number of Texas reservoirs and streams. Minnows, crayfish, and alderfly larvae (hellgrammites) are among the most successful live baits used. Smallmouth bass now rank among the top 15 most preferred species. Known maximum size in Texas exceeds 7.5 pounds.
Smallmouth bass prefer large clear-water lakes (greater than 100 acres, more than 30 feet deep) and cool streams with clear water and gravel substrate. In small streams a fish's activity may be limited to just one stream pool or extend into several. Spawning occurs in the spring. When water temperatures approach 60°F males move into spawning areas. Nests are usually located near shore in lakes; downstream from boulders or some other obstruction that offers protection against strong current in streams. Mature females may contain 2000-15,000 golden yellow eggs. Males may spawn with several females on a single nest. On average each nest contains about 2,500 eggs, but nests may contain as many as 10,000 eggs. Eggs hatch in about 10 days if water temperatures are in the mid-50's (°F), but can hatch in 2-3 days if temperatures are in the mid-70's (°F). Males guard the nest from the time eggs are laid until fry begin to disperse, a period of up to a month. As in other black bass, fry begin to feed on zooplankton, switching to insect larvae and finally fish and crayfish as they grow.
Smallmouth bass originally ranged north into Minnesota and southern Quebec, south to the Tennessee River in Alabama and west to eastern Oklahoma and southwestern Arkansas. Today there are few states, east or west of the Rocky Mountains, where populations have not become established. Florida and Louisiana are apparently free of smallmouth bass. In Texas the species has been stocked in numerous areas, particularly streams of the Edwards Plateau.