Walleye

The walleye is a large freshwater fish in the family Percidae, native to lakes and rivers across much of North America, particularly Canada and the northern United States. It is named for its large, glassy, light-reflective eyes, an adaptation that results from a layer of tissue (the tapetum lucidum) that enhances vision in low light and murky water. Walleye have an elongated body, golden-olive coloration, and a spiny first dorsal fin with a characteristic black blotch. They are among the most widely distributed and popular freshwater game fish in North America and are generally classified as of Least Concern, though some regional stocks are managed carefully to sustain fisheries.

Identification features of the walleye:

• Elongated, moderately compressed body with golden-olive to brassy coloration
• Large, glassy, silvery eyes that appear to glow in reflected light
• Dark, mottled saddle-like blotches along the back and upper sides
• Two dorsal fins: a spiny first dorsal with a distinct black blotch near its rear base, and a soft second dorsal
• White tip on the lower lobe of the tail fin

Adults typically measure 38-76 cm. Walleye are distinguished from the closely related sauger by the black dorsal fin blotch and white-tipped tail, which sauger lack.

Walleye inhabit cool, freshwater lakes, reservoirs, and rivers across much of Canada and the northern and central United States, favoring water temperatures in the cool to moderate range. They prefer moderately deep, often turbid or low-light water, and are highly light-sensitive, typically retreating to deeper or shaded areas during bright daylight and moving into shallower water to feed at dusk, dawn, and night. Walleye favor structure such as rocky points, drop-offs, and weed edges, and can tolerate a range of water clarities, though they generally avoid very clear, brightly lit shallow water during the day.

Walleye are primarily crepuscular and nocturnal predators, using their light-sensitive eyes to hunt effectively in low-light and turbid conditions, feeding mainly on smaller fish along with some invertebrates. They often school loosely, especially as juveniles, becoming more solitary as they mature. Walleye spawn in early spring, typically over rocky or gravel substrate in shallow water or tributary streams, scattering adhesive eggs with no parental care. Their reliance on low light for feeding means activity levels often shift with cloud cover, water clarity, and time of day. As a widespread apex or near-apex predator in many northern lake systems, walleye play a significant role in regulating prey fish populations.