As anglers cast lures into Minnesota’s lakes and rivers this time of year, native mussels lurking on the bottoms of those water bodies are also luring fish — with a surprising bait-and-switch move.
Female mussels become masters of disguise by waggling soft body parts that astonishingly replicate the shape, colors and movements of worms, minnows and small fry to get the attention of hungry fish.
As the fish dart toward them, mussels shoot a cloud of fertilized eggs known as glochidia into the fish’s face. Glochidia attach to fish and continue to grow while attached to their gills, getting nutrients from fish, but not harming them.
Within 10 days to six weeks, when they’re big enough to survive independently, the glochidia drop down to river and lake bottoms.
Various species need specific fish and specific lake and stream beds for it all to work.
“We have about 50 species of freshwater mussels that are native to our state,” said Alan Holzer, an interpretive naturalist with Three Rivers Park District’s Mississippi Gateway Regional Park. “They’re in every river, almost every lake and permanent creek. We’re really lucky to have this kind of diversity.”
Minnesota’s native mussels have names that sound like playground insults, including pigtoe, fatmucket, giant floater, heelsplitter, and pimpleback.
When they aren’t choked out by invasive zebra mussels, native mussels play a vital role keeping Minnesota’s waterways healthy. They draw in water to get oxygen and nutrients and expel clarified, cleaner water, leading to their nickname as “the liver of the river,” Holzer said.
