Fish
Walleye
Sander vitreus · also called walleyed pike, yellow pike, pickerel
The walleye is the fish that the Upper Midwest and much of Canada organise their weekends around. It is a big, golden, toothy member of the perch family, and its defining feature is an eye built for the dark — a mirror behind the retina that lets it hunt when other fish cannot see.
Overview
Sander vitreus lives in large lakes, reservoirs, and rivers across central and northern North America. It is olive-gold with dark saddles, a spiny dorsal fin, canine teeth, and a white-tipped lower tail. It eats mainly other fish. Despite names like “walleyed pike,” it is a percid, related to the yellow perch.
The mirror eye
A reflective layer, the tapetum lucidum, sits behind the retina and bounces light back through it, giving the walleye superb low-light vision — and the cloudy, outward look that names it. Bright sun actually hampers it, so it feeds at dawn, dusk, night, and on windy or overcast days, holding deep when the sun is high.
The prize fish
Across the Great Lakes region, the walleye is the most valued freshwater food fish, central to fish-fry culture, and the target of an enormous sport and commercial fishery.
Status
Least Concern and intensively managed. Big stocks like Lake Erie’s swing between boom and bust with weather, prey, and fishing pressure.
Walleye: common questions
Why is it called a walleye?
The name comes from the eyes, which look cloudy, silvery, and outward-turned, like the "wall eye" once used to describe a horse or a person with a pale, divergent eye. The milky appearance is caused by the tapetum lucidum, a mirror-like layer of reflective crystals behind the retina. It reflects incoming light back through the light-sensing cells a second time, roughly doubling the chance that a dim photon is detected, which is why the walleye can see and hunt in conditions close to total darkness. The same layer is what makes a cat's or a deer's eyes shine in a headlight.
When is the best time to catch walleye, and why?
Low light. Because its eyes are tuned for the dark, a walleye is actually at a disadvantage in bright midday sun, which washes out the contrast it relies on to see prey, so it feeds most in the hours around dawn and dusk, after dark, and on grey, choppy days when the surface breaks up the light. Anglers talk about the "walleye chop", a stiff breeze that ruffles the surface and triggers daytime feeding, and many target the fish at night or in the low-angle light of early morning and late evening, working the edges of drop-offs, weed beds, and rocky points.
Is walleye related to European pike-perch?
Yes, closely. The European zander, or pike-perch, is in the same genus, Sander, as the walleye and looks and behaves much like it, a toothy, low-light-hunting predator of large lakes and slow rivers valued as a food fish. The walleye and sauger are the North American members of the genus and the zander is the main European one, along with a couple of smaller relatives. Zander have been introduced to parts of Britain and elsewhere, where they are sometimes treated as an invasive predator, much as walleye can be when stocked outside their native range.
How big do walleye get?
A typical keeper walleye is 35 to 55 centimetres and half a kilogram to a kilogram and a half. Fish over 70 centimetres and 4 kilograms are trophies, and the largest come from productive southern reservoirs and a few big northern lakes, where a female can exceed 60 centimetres and live 20 years or more. The all-tackle world record, a fish from Old Hickory Lake in Tennessee in 1960, weighed about 11.3 kilograms, though that figure has been questioned. In most waters a walleye of 5 kilograms is the fish of a lifetime.