Behold the spiny water flea: a single black eye, a barbed tail, and it reproduces asexually. Small fish, like young walleyes and yellow perch, can't eat it because of the spiny tail.
Then to add insult to injury, it turns around and eats the very things those same young fish eat - and out-competes them - leading to slower-growing bigger fish. Plus it's decimating populations of the zooplankton that help keep algae in check and lake systems in balance.
In a recent interview, with Dr. Donn Branstrator, the Co-Director of the Water Resources Science Graduateprogram at UMD, National Geographic (Tim Folger, "This ferocious water flea is mauling the Great Lakes," December 2, 2020) said "the tiny invader has already permanently altered the base of the food web on which all the lakes’ fish depend."
What does it want? "Indefinite persistence." How do you stop it? Dry gear and Swedish dish cloths.
You can find out more about ways to stop the spiny water flea here at the Minnesota Aquatic Invasive Species Research Center (MAISRC) website, including information on how to get a dishcloth: