When swimming in a lake do you really know what creature lurk beneath? For all you know it could be Loch Ness or a shark? Ok not really but if you've ever seen a Muskellunge (often called a "muskie)" or a big Northern Pike up close they may as well be called freshwater sharks with mouths full of razor sharp teeth.
In honor of Shark Week on Discovery Channel thought this video was fitting. While it's not from Wisconsin it's still cool.
Two Minnesota kayakers came upon an odd meeting between a muskie and a northern pike. Didn't end well for the pike, apparently.
Ridder's had a similar experience while fishing in Canada between a Muskie and a Smallmouth Bass.