Close to a half-million anglers will venture out onto Minnesota lakes Sunday for two of Minnesota's prized catches, the walleye and the northern pike. Yes, it's the great Minnesota Fishing Opener!

The word "walleye" is actually derived from an old Norse word meaning "a light beam in the eye." The walleye's eyes seem to glow because they have a light-sensitive layer of cells that allows the fish to see and feed in the dim light of murky lakes and at dawn and dusk. The walleye also has unusually large, color-sensitive cells. Good eyesight helps this carnivore catch its food, which consists of fish, even other walleyes, plus leeches, crayfish and other marine animals.

Some people refer to the walleye as a "pike" but it's actually America's largest perch. Adults range from 2 to 8 pounds, and they never stop growing, so lunkers can reach 15 pounds or more. Long considered Minnesota's most popular fish, the walleye became the official state fish in 1965.

The walleye is native to many lakes and streams throughout Minnesota, and also has been widely introduced. In fact, walleyes can be found in more than 1,700 lakes in the state and in more than 3,000 miles of river habitat. Its preferred habitat is free of pollution and also provides cover and food, plus rock and gravel spawning shallows. The walleye has a broad distribution in North America from the Northwest Territories east to Labrador and south to North Carolina and Arkansas.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.