No, this is not news from The Onion, but a research report published in Biological Invasions on March 6, 2023. This was a rare case of a zebra mussel attached by byssal threads to the lateral scales of a 6” lake chub. In the abstract, the authors note that Charles Darwin had previously recognized the potential for this kind of animal-assisted dispersal to occur. Also of note is that in 1882 Darwin published research entitled “On the dispersal of freshwater bivalves”