Males build and guard nests in colonies. Crappie are prone to stunting. Because a strong year-class often dominates in a lake, crappie often appear to be all of the same size. When these fish of a strong year-class grow large, the lake can gain a reputation as a crappie hot spot and then fade into mediocrity as a younger year class takes over. Young crappie eat small aquatic invertebrates.
Adults can continue to feed on plankton but usually eat a lot of small fish as well.
Crappie may compete with walleye to some degree because their habits are similar. Both species travel open water in schools, feeding on similar foods at night, dawn and dusk. The most effective management is the protection of habitat and maintenance of good predator-prey balance in the lake. Stout and heavy in comparison to the sunfishes and crappies, the rock bass has red eyes and brassy flanks with black spots. A large rock bass measures about 10 inches and weighs about a pound.