Walleye, Canadian IQF
Walleye is a freshwater fish native to most of
Canada and to the northern United States.
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.
The name, "walleye" comes from the fact that their
eyes, like those of cats, reflect light. This "eyeshine" 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.
The fish's eyes also allow them to see well in
turbid waters which gives them an advantage over their prey. This
excellent vision also allows the fish to populate the deeper regions in
a lake and they can often be found in deeper water, particularly during
the warmest part of the summer.
Walleyes are largely olive and gold in colour. 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.
Walleyes grow to about 80 cm (31 in) in length, and
weigh up to about 9 kg (20 lb). The maximum recorded size for the fish
is 107 cm (42 in) in length and 11.3 kilograms (25 lb) in
The growth rate depends partly on where in their
range they occur, with southern populations often growing faster and
larger. In general, females grow larger than males.
Walleyes may live for decades; the maximum recorded
age is 29 years. In heavily fished populations, however, few walleye
older than 5 or 6 years of age are encountered. In North America, where
they are heavily prized, their typical size when caught is on the order
of 30 to 50 cm (12 to 20 in), substantially below their potential
In most of the species' range, the majority of male
walleyes mature at age 3 or 4. Females normally mature about a year
later. Adults migrate to tributary streams in late winter or early
spring to lay eggs over gravel and rock, although there are open water
reef or shoal spawning strains as well.
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. Most commercial fisheries for walleye are situated in the Canadian
waters of the Great Lakes, but there are other locations as