Clear waters of large streams and medium-sized lakes, and aquatic vegetation over bottom of sand, muck, or aquatic debris. Intolerant of turbid waters. Inhabits heavily vegetated, shallow waters in spring, moving in summer to roam or suspend over deep water. Insects and their larvae remain an important food item throughout life, but feeds on small fish and minnows from second. Adults continue to feed on plankton but usually eat plenty of small fish.
Large adults are mostly piscivorous, and efficient predators of small fish.
May compete with Walleye to some degree because of similar habits. Both travel open water in schools, feeding on similar foods at night, dawn, and dusk. Flesh is flaky, white, and considered very tasty. Female lays 20,000 to 60,000 eggs, occasionally up to 150,000. Male guards nest and defends young until they start to feed.