The Walleye is a freshwater perciform fish native to most of Canada and to the northern United States. The walleye is sometimes also called the yellow walleye to distinguish it from the blue walleye.In some parts of its range, the fish is known as the yellow pike or pickerel, although the use of these names should be discouraged since the fish is related neither to the pikes nor to the 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.