Here’s to Hoover-Mouth

There are species of fish in your lake that you may rarely if ever see, yet are important to the health of the fishery. The white sucker is a classic example.

You may know this fish best as bait. Raised in ponds, it is sold in increasing sizes for walleyes, northern pike and muskies. If like me you grew up on a Lake Michigan tributary, you may have fished for suckers using a dip net hung by a rope from a bridge, in springtime when the fish migrate upriver from the lake to spawn.

If your lake contains suckers, why don’t you see them? Well, because they tend not to take what anglers offer. I’ve fished for more than 50 years and have caught just one white sucker from a lake on hook and line.

Suckers are mainly bottom-feeders and have mouths well adapted to that purpose. The leathery lips aim downward instead of straight ahead, so the fish can cruise along, dining in comfort, casually vacuuming up food like insect larvae, worms, small mollusks and crustaceans, plant matter and fish eggs from the sediment. In turn, suckers are a vital food for favored game fish; they may also be eaten by herons, loons, bald eagles and osprey.

White suckers live in almost any lake and stream here in Northern Wisconsin. In fact, they’re abundant throughout the Northeast and Midwest U.S. and in parts of the Northwest. They do fine in clear, clean waters but also tolerate relatively low dissolved oxygen and so can thrive in turbid urban waterways.

Suckers have fine scales. Sides are dark greenish with a metallic luster; the belly white, and hence the common name. Adults can grow up to 20 inches long and weigh two pounds or more; musky anglers are known to use those at the top of the size range for bait in the fall.

Spawning generally starts when the fish are about four years old (later in colder climates where they grow more slowly). Spawning season runs from April to early May. The fish move into streams or, in lakes, select bottoms of gravel or coarse sand. The actual spawning happens at night. Most often, two males mate with one female. With one male to each side, the female lays 20,000 to 50,000 eggs, which the males fertilize.

The fish do not make spawning nests and do not care for the eggs, which simply sink to the bottom. The eggs hatch in five to ten days, and a week or two later the fry leave the spawning area and disperse.

Thus are born swarms of fish on which your lake’s most prized species may depend for growth. So even if you never see suckers on your lake except in your bait bucket, be sure to assign them a little respect. Here’s to Hoover-Mouth!