The walleye has teeth on its jaws and the roof of its mouth. The first dorsal fin has dark blotches, and the lower lobe of the tail fin is white. The back and sides are yellow or green-brown with dark blotches. The average length for a walleye is 12 to 28 inches. The name "walleye" comes from the opaque appearance of the eye, which is due to a light-gathering structure. The walleye lives about seven or eight years.
The walleye lives in the open water of lakes and reservoirs and in stream pools. These fish live in small groups that swim over a wide area. It is active at night, moving to shallow water to feed and returning to deep water in the day. The walleye spawns at night from February through April. It moves out of large rivers and reservoirs into smaller tributaries to spawn. There is no nest preparation or parental care. Eggs are scattered on the bottom and hatch in about seven days. The walleye eats insects and fishes.