Monsters of the Deep — September - October 1999

by Tom Dickson

Monsters of the Deep: Illustration of an angler holding a fish

A 3-pound crappie is a huge crappie. But it's nothing compared to Minnesota's really big fish. Some of these monsters of the deep would eat a crappie like that for breakfast--and still have room for more.

Minnesota's six biggest fish are the lake sturgeon, flathead catfish, muskellunge, carp, paddlefish, and northern pike. Their top sizes range from 55 pounds (pike) to 300 pounds (sturgeon).

Catching big fish usually requires big lures. Muskie and northern pike anglers use lures as big as corn cobs.

But some big fish eat tiny things. You can catch a big carp on a single kernel of canned corn, or a large sturgeon with a few worms.

Sometimes you don't need anything to land a huge fish. In 1998, a sturgeon weighing 105 pounds washed up dead on the shores of Lake Harriet in Minneapolis. Sturgeon weren't even supposed to live in that lake. How did it get there? And what other lakes contain huge fish that no one knows about?

Lake Sturgeon

Imagine a fish that weighs more than your dad. Or even more than your mom and dad combined. That's how big a lake sturgeon can grow.

Lake sturgeons are the largest freshwater fish in Minnesota. Records from the 1800s show that these fish reached more than 300 pounds and were more than 8 feet long. Today, anglers in Minnesota occasionally catch them weighing 80 or 90 pounds. This past May, an angler caught one in Lake of the Woods that weighed 91 pounds and measured 5 feet, 7 inches long. That's longer than most ninth-graders are tall.

Sturgeons are strange, prehistoric fish. Unlike most fish, they don't have scales. Instead of eating with teeth, they suck up underwater insects with a mouth like a vacuum cleaner hose. Instead of bones, their skeletons are made of cartilage. They are so big that people don't frighten them. Biologists who study sturgeons say these fish will swim gently between their legs. "I think they actually like people," says one biologist.

State record: 94 pounds, 4 ounces, Kettle River, 1994

World record: 168 pounds, Ontario, Canada, 1982

How to Fish for Sturgeon

Bait: Sturgeon anglers use a single large hook with three large night crawlers. A grape-sized sinker keeps the bait down on the bottom.

Where to Fish:The only places it's legal to fish for sturgeon in Minnesota are on the Rainy River and in Lake of the Woods, both on the Canadian border, and on part of the St. Croix River. (The Kettle River, home to Minnesota's state record, is now closed to lake sturgeon fishing.)

When: The best fishing on Rainy River and Lake of the Woods is in late spring and summer.


The paddlefish is another gentle giant. Its body is shaped like a shark's. Like the shark and sturgeon, the paddlefish has a skeleton made of cartilage rather than bone. It has a huge mouth like a cave. Its snout looks like a canoe paddle.

Despite its fierce appearance, the paddlefish is harmless. It eats only tiny drifting animals and plants, called plankton. A paddlefish collects plankton in its huge mouth and traps them in comblike structures called gill rakes.

Paddlefish were once common in the Mississippi, Minnesota, and St. Croix rivers. But no longer. Paddlefish began to disappear after dams were built on the Mississippi. The dams created lakes that flooded the gravel bars where the fish laid their eggs. The dams also blocked the paddlefish from reaching gravel bars on tributaries. Because there are so few remaining, paddlefish are protected in Minnesota. Paddlefish angling is not allowed here.

Anglers rarely catch paddlefish anyway because the fish usually ignore worms, minnows, and other baits.

No one knows what the paddlefish does with its paddle. Scientists once believed that the fish used it to stir up the river bottom and find insects. The paddle is covered with taste buds. These may help the big fish find food. Recently scientists have learned that the paddle acts as an antenna that senses weak electrical impulses given off by plankton.

State record: Paddlefish are protected in Minnesota, though accidental catches of more than 50 pounds have been recently reported.

World record: 142 pounds, 8 ounces snagged in the Missouri River, Montana, 1973


A muskellunge is like a tiger that swims. Also known as a muskie, this large predator grows to more than 50 pounds. A muskie eats fish and sometimes ducklings and even small muskrats. It waits in weed beds for something to swim by. Then it lunges forward, clamping its large, tooth-lined jaws onto the prey. The muskie then gulps down the stunned or dead victim head first.

Muskies are silver, light green, or light brown. Most have dark bars running up and down their long bodies. But some have faint spots or have almost no markings at all.

Do muskies bite humans? Almost never. The most recently reported case was in 1995 on Lake Rebecca in Minneapolis. That summer, a muskie bit the hand of a 14-year-old swimmer.

When hooked, a muskie leaps into the air, twisting wildly to throw the hook from its jaws.

A cousin to the muskie is the northern pike. Northerns aren't as big--"only" up to 45 pounds--but they are far more common.

State record: 54 pounds, Lake Winnibigoshish, 1957

World record: 67 pounds, 8 ounces, Hayward, Wis., 1949

How to Fish for Muskellunge

Lures: Anglers use gigantic crankbaits or spinners with two or three large treble hooks. Fly anglers tie huge, freakish muskie flies out of bright feathers, colored deer hair, sparkling tinsel, and strips of dyed rabbit skin.

Where to fish: Minnesota's best muskie lakes are Lake of the Woods, Rainy Lake, Leech Lake, Cass Lake, and Lake Winnibigoshish. Top muskie rivers are the Mississippi, Big Fork, and Little Fork.

Flathead Catfish

picture of a flathead catfish

Flatheads have huge, flat heads. On a really big flathead, the mouth is so humongous you could put a cantaloupe inside. Flatheads have a squared-off tail. Minnesota's other large catfish, the channel catfish, has a forked tail. Like other catfish and bullheads, flatheads have no scales.

In Minnesota, flatheads are found in big rivers. They wait in deep holes for big minnows to swim past. The best fishing is at night, when catfish feed.

The name catfish comes from the fish's whiskers, called barbels. Catfish use their barbels, which are covered with taste buds, to find food in muddy water.

Catfish don't have stingers, as some people believe. But they do have three sharp spines, one each on the dorsal (top) and two pectoral (side) fins. The spines are sharp but not poisonous.

People in some states catch large flathead catfish by a technique called noodling. In spring noodlers wade rivers, sticking their arms under the banks in search of an underwater muskrat den. Catfish use these as a nest. There, the male flathead guards the eggs, biting any other fish that comes near. When the noodler's hand appears, the catfish opens its jaws and bites down. Noodlers then grab the fish's lower jaw or gill opening and haul the fish onto the bank. Noodling, which can be dangerous, is illegal in Minnesota.

State record: 70 pounds, St. Croix River, 1970

World record: 123 pounds, 9 ounces Independence, Kan., 1998

How to Fish for Catfish

Lures and baits: Flatheads sometimes attack lures such as crankbaits. But usually they are caught using live bait such as gizzard shad or big minnows.

Where to fish: Minnesota's best flathead rivers are the Mississippi, St. Croix, and Minnesota.


The biggest fish many anglers catch in their lives is a carp. Walleyes average 1 to 2 pounds. Carp, a Eurasian fish found throughout Minnesota, average 3 to 6 pounds, and catching a 10- or 15-pounder is not uncommon. Most experienced anglers have caught at least one carp, and they rarely forget how strong it was.

Minnesota's state record carp was once also the world record. But over the past 20 years, much larger carp have been caught throughout the world.

Carp have large scales, a sucker mouth, and two pairs of barbels, which help carp find food.

Carp are the most widely eaten freshwater fish in the world. They are the most popular sport fish in Europe. For years, American anglers considered carp a trash fish. But lately, anglers have begun to admire the carp's strength and fighting ability. A few years ago, In-Fisherman magazine said the carp could soon become "the world's greatest sportfish."

State record: 55 pounds, 5 ounces, Clearwater Lake, 1952

World record: 82 pounds, 3 ounces, Romania, 1998

How to Fish for Carp

Baits: Carp eat a wide range of foods. The most popular baits are night crawlers, canned corn, and small balls of dough flavored with Kool-Aid, honey, or molasses. (Carp don't have teeth, but they do have a sweet tooth.)

Where to fish: Some of the biggest carp have come from the Mississippi, St. Croix, and Minnesota rivers, and from Mille Lacs, Minnetonka, and Bald Eagle lakes.

A complete copy of the article can be found in the September - October 1999 issue of Minnesota Conservation Volunteer, available at Minnesota public libraries.

Tom Dickson is staff writer for the DNR Division of Fish and Wildlife and interim editor of the Volunteer. He is also co-author of A Guide to Rough Fish, Fishing for Buffalo.