They're called Garra rufa, they eat dead human skin when there's no plankton around, and they are part of beauty treatments around the world, where people get "fish pedicures."
And they might have caused a woman's toenails to fall off.
As reported at CNN.com, the woman began showing signs of onychomadesis, whether the toenails fall off after something impedes the nail's growth. The patient didn't have the typical markers that most patients have, so the doctors reported in the JAMA Dermatology Journal.
To learn more, check out the original article here.