Tadpole Madtoms (Noturus gyrinus) demonstrating their traditional tail slap, usually used to celebrate stinging the hell out of unsuspecting humans. These guys didn't get me. Clam River (tributary of St. Croix River), Burnett County, WI. Captured in dip-net. Aug. 7, 2016. Shot in photo tank with 90mm macro. (Photo altered, cleaned and adjusted in Photoshop to blur background, remove suspended sand, etc. Color pretty much unaltered. I used a sanded piece of plexiglass as a background. It looked uniformly frosted to the naked eye, but macro view shows individual scratches. Back to the drawing board on that.)