WALLEYE

Walleye or yellow pickerel or pickerel (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. In some parts of its range, the walleye is also 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.
The common name, "walleye," comes from the fact that their eyes, like those of cats, reflect light. This eye shine is the result of a light-gathering layer in the eyes called the tapetum lucidum which allows the fish to see well in low-light conditions. In fact, many anglers look for walleyes at night since this is when most major feeding patterns occur. Their eyes also allow them to see well in turbid waters (stained or rough, breaking waters) which gives them an advantage over their prey. Thus, walleye anglers will commonly look for days and locations where there is a good "walleye chop" (i.e., rough water). This excellent vision also allows the fish to populate the deeper regions in a lake and can often be found in deeper water.
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.
Walleyes grow to about 75 cm (30 in) in length, and weigh up to about 7 kg (15 lb). The maximum recorded size for the fish is 107 cm (42 in) in length and 11.3 kg (25 lb) in weight.