Males move to spawning areas before females. In large lakes, spawning may occur in shallow water or in deep water. Cisco are a schooling fish, usually frequenting deep water. They move to shallower water in fall as upper waters cool. They are primarily plankton feeders, though insects and small minnows are eaten on occasion.
Cisco are an important food for large game fish.
The flesh of these fish is palatable. It is caught commercially and sought by sport fishermen in the fall using flies and small minnows. It is also caught through the ice on jigs.