At least a half-million anglers will venture out onto Minnesota lakes this weekend for the chance to catch a walleye. Yes, it's the great Minnesota fishing opener.

Our state is home to more than 160 species of fish, but the walleye is synonymous with fishing in Minnesota. It became the official state fish in 1965. The average angler spends between three and four hours catching each walleye, according to our Department of Natural Resources.

The walleye is named for its pearlescent eye, a reflective layer of pigment that helps 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 these carnivores catch their food, which consists of fish, even other walleyes, plus leeches, crayfish and other aquatic inhabitants. The preferred walleye habitat is pollution-free, provides cover and food, and has rock and gravel spawning shallows. The walleye has a broad distribution in North America, from the Northwest Territories in Canada eastward to Newfoundland and Labrador and south to North Carolina and Arkansas.

The walleye is native to many lakes and streams throughout Minnesota. It's also been widely introduced. Some of the state's best known walleye lakes include Lake of the Woods, Vermilion, Upper and Lower Red, Leech, Cass, Winnibigoshish and Mille Lacs. In the Twin Cities area, lakes Minnetonka and Waconia provide some good walleye fishing.

Anglers, be sure to wear a life jacket and respect the water. It's in the 40-degree range and can be dangerous.

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. He taught and worked as a naturalist for 50 years.