The walleye (Sander vitreus, synonym Stizostedion vitreum), also called the yellow pike or yellow pickerel, is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a subspecies that was once found in the southern Ontario and Quebec regions, but is now presumed extinct. However, recent genetic analysis of a preserved (frozen) 'blue walleye' sample suggests that the blue and yellow walleye were simply phenotypes within the same species and do not merit separate taxonomic classification.

In parts of its range in English-speaking Canada, the walleye is known as a pickerel, though the fish is not related to the true pickerels, which are a member of the family Esocidae.

Walleyes show a fair amount of variation across watersheds. In general, fish within a watershed are quite similar and are genetically distinct from those of nearby watersheds. The species has been artificially propagated for over a century and has been planted on top of existing populations or introduced into waters naturally devoid of the species, sometimes reducing the overall genetic distinctiveness of populations.

Description
Walleyes are largely olive and gold in color (hence the French common name: doré—golden). The dorsal side of a walleye is olive, grading into a golden hue on the flanks. The olive/gold pattern is broken up by five darker saddles that extend to the upper sides. The color shades to white on the belly. The mouth of a walleye is large and is armed with many sharp teeth. The first dorsal and anal fins are spinous, as is the operculum. Walleyes are distinguished from their close relative the sauger by the white coloration on the lower lobe of the caudal fin, which is absent on the sauger. In addition, the two dorsals and the caudal fin of the sauger are marked with distinctive rows of black dots which are absent from or indistinct on the same fins of walleyes.

Food
The walleye is considered to be a quite palatable freshwater fish, and consequently, is fished recreationally and commercially for food. Because of its nocturnal feeding habits, it is most easily caught at night using live minnows or lures that mimic small fish. In Minnesota, the walleye is often fished for in the late afternoon on windy days (known as a "walleye chop") or at night. Most commercial fisheries for walleye are situated in the Canadian waters of the Great Lakes. Often served as a sandwich in Minnesota's pubs where the fish is very popular, deep fried walleye on a stick is a Minnesota State Fair food

Source
Wikipedia