Sander vitreus, (Mitchill. 1818)
Walleye have extremely keen eyesight, even in low light conditions. This ability allows walleye to be highly successful predators at night and at dusk and dawn. The oldest reported age for a walleye is 29 years. The heaviest published weight for a walleye is 11.3 kg (25 lbs.) A sub-species of walleye (Blue Walleye), that formally inhabited Lake Erie and Ontario is now extinct. Populations of this sub-species are still present in Canada.
SIZE: The common length for walleye is around 54 cm (22.3 in) with the maximum reported length being 107 cm (42 in).
RANGE: Walleye in North America are found in the Arctic south to the Great Lakes and across to the St. Lawrence River. In Canada, walleye are found in Quebec across to the Northwest Territories. Within the United States, walleye are found southward into Alabama and Arkansas and in the Mississippi River basin. Walleye have been widely introduced outside of their native range within the U.S., including the Atlantic and Pacific Ocean drainages and in the Gulf of Mexico.
HABITAT: Walleye occur in lakes, pools, back waters and runs of medium to large rivers. Walleye prefer large shallow lakes with high turbidity. Walleye are rarely found in brackish water.
DIET: Juvenile walleye feed on invertebrates and small fish. Adult walleye feed mostly on fish such as yellow perch and minnows, but dozens of fish species have been found in walleye stomachs. Adults will also feed on crayfish, snails, frogs, mudpuppies and small mammals when fish and insects are scarce.
Walleye are a potamodromous species. Spawning occurs in small groups that engage in chasing, circular swimming, and fin erection. The spawning group will then move to shallow water, where the females will roll on their side and release their eggs and the males will then immediately release their milt to fertilize the freshly extruded eggs. All of the egg and milt deposition normally occurs during a single night.
Great Lakes walleye populations have been overfished resulting in population declines in parts of the Great Lakes drainage basin. Great Lake states manage walleye populations through habitat protection, walleye rearing and stocking and fishery management regulations that delineate harvest methodologies such a gear types, seasons, creel limits and size limits.
There are indications that climate change is impacting natural walleye habitat distribution. Recent climate changes may be driving the displacement of walleye populations by warm water or temperate species such as sunfish, largemouth and smallmouth bass.
The National Fish Hatchery System(NFHS) and the Fish and Wildlife Conservation Offices(FWCO) of the U.S. Fish and Wildlife Service have been supporting the states in the conservation and management of their walleye resources.