Species overview: Walleyes (Sander vitreus) are native to central North America and Canada, including the Ohio River and Great Lakes watersheds. A popular sport fish, they have been extensively stocked. In Pennsylvania they are now found throughout the state, including the Susquehanna and Delaware River watersheds, as well as their original Allegheny River and Lake Erie watershed homes. One of the walleye’s nicknames is “Susquehanna salmon.” It has also been called “yellow pike” and even “pickerel.” All these nicknames put it in the wrong fish family–it’s neither a pike cousin nor a salmon. It’s the biggest, toothiest member of the perch family in North America. The name “walleye” refers to the fish’s large, milky eye that looks luminous when light is shined on it. The eye has a reflecting membrane behind the retina, which causes this effect. The species name “vitreum” means “glassy,” and refers to the luminous eye.

Identification: Walleyes have a long, roundish body, a forked tail and sharp canine teeth in their jaws. The large eye is glassy and reflects light at night. The dorsal fin is separated into two parts, the front portion with 12 to 16 spines, the rear portion with one or two short spines and the rest, soft rays. The anal fin has one or two spines. Walleyes vary in color, ranging from a bluish gray to olive-brown to golden-yellow, with dark-on-light mottling. Side scales may be flecked with gold. Irregular spots on the sides can join to make a vague barred pattern. The belly is light-colored or white.

One way to distinguish a walleye from its cousin, the sauger, is to look for the walleye’s dark spot at the rear edge of the front (spiny) section of its dorsal fin. Also, on the walleye, the lower portion of the tail fin is whitish, and so is the bottom margin of its anal fin.

Habitat: Walleyes live in large lakes, big streams and rivers. They are rarely found in lakes smaller than 50 to 100 acres. Walleyes are abundant in water that is cool and moderately deep, with a gravelly, sandy or rocky bottom. They tolerate turbid and clear water conditions. Walleyes also need relatively cool water, where summer temperatures do not exceed 85 degrees. They use extensive gravel or rubble areas for spawning, and typically inhabit lakes or rivers that have expansive areas deeper than 10 feet.

Life history: Walleyes travel, feed and spawn in schools. They range widely in their home lakes or rivers. Walleyes are one of the first fish to spawn in the spring, sometimes even before the ice has completely melted from the surface or around the shoreline. They return year after year to their spawning sites, sometimes traveling a long distance, so they truly make a “spawning run.” The spawning site may be rocky or gravelly shoals or shallows in a lake or river cove at the base of dams or riffles, or the walleyes may travel up a tributary stream to spawn over flooded marsh grass.

The females move into the spawning area first, when water temperatures reach 45 to 50 degrees. The eggs are scattered randomly. The females spawn with several males, usually at night. Eggs are commonly deposited where there is some water movement, whether from stream flow or wave action near the edges of the lake. After they are extruded, the eggs fall into protective spaces in the rocks and gravel. Walleye eggs hatch in about 12 to 18 days, depending on water temperature. Females produce 25,000 eggs per pound of body weight, so a single large female could spawn 500,000 minute eggs or more. When they hatch, walleye fry are about a half-inch long and paper-thin. At first they drift about, absorbing the yolk sac.

Young walleyes feed on microscopic animals, or zooplankton. When they reach several inches long, walleyes switch to other small fish as their primary food. Like the adults, they spend much of their time in deep water, moving closer to shore during mornings and evenings to feed. Typically, adult walleyes feed at dusk during the cooler months and at night during the summer. In turbid water, walleyes can be active during the day. The light-reflective coating behind the walleye’s retinas, which gives the eye the glowing appearance, is an adaptation to feeding at night and in dim light. Walleyes are often the top predator fish in their habitat, eating other fishes, as well as frogs, crayfish and large insect larvae.

Walleyes can grow to 36 inches. The state record is over 17 pounds. Although walleyes can be caught at any time of day, night fishing or fishing the dim depths with live bait or fishlike lures and jigs is effective for catching walleyes.