The smallmouth bass prefers waters that are cool, usually sixty-eight to seventy degrees Fahrenheit, and clear, where there are rocks and gravel at the bottom. These fish look for a habitat, containing a protective cover of submerged logs, shoal rocks, or talus slopes. The smallmouth bass occasionally lives ten to twelve years old, and the average fish caught is less than three pounds, and eight to fifteen inches long. The easiest way to tell the difference between a small mouth and a large mouth bass is, well, the size of their mouths. The rear end of the lower jaw in a smallmouth does not extend past the eye, while the rear end of the lower jaw in a largemouth, does.
Any activity involving spawning starts in the spring, when the waters are sixty degrees Fahrenheit or more. The male builds a nest in quiet water, typically downstream from an obstruction that causes a break in the current, or near shore, and the female then swims near and lays her eggs, much like the largemouth bass. The nest is never far from deep water though, because the male guards the eggs and newly hatched fry, and so wants to have a place he can escape to if frightened. The eggs hatch in two to three days, but after that the fry drop down into the bottom of the gravel nest to rest for three or more days. Newly hatched, the fish eat micro crustaceans, but as they grow, they start eating insects and fish also, and from one year old on, they eat mostly fish and crawfish, including minnows, yellow perch, and sunfishes.