Walleye (Sander vitreus, formerly Stizostedion vitreum) 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 pikeperch. The walleye is sometimes also called the yellow walleye to distinguish it from the blue walleye, which is an extinct subspecies formerly found in the southern Great Lakes.

In some parts of its range, the walleye is mistakenly known as the colored pike, yellow pike or pickerel (esp. in English-speaking Canada), although the fish is related neither to the pikes nor to the other pickerels, both of which are members of the family Esocidae.

Genetically, 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.

Source:
http://en.wikipedia.org/wiki/Walleye