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 called the yellow walleye to distinguish it from the blue walleye, which is a subspecies that can be found in the southern Ontario and Quebec regions.[1] In some parts of its range, the walleye is known as the walleyed pike, colored pike, yellow pike or pickerel (esp. in English-speaking Canada), although the fish is not related to other species of pikes which are members of the family Esocidae.[2] 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.