For some freshwater mussel species, a host is necessary for it’s larvae (glochidia) to develop and disperse. Most of the time, the host animal is a fish. As such, mussels have some amazing strategies to attract the appropriate host. Some mussels go fishing by waving a minnow-like lure (a modification of the mantle) in the stream current. If successful, the glochidia attach themselves to the gills or fins of a fish attracted to the lure. The fish carries the mussels for 3 weeks to several months depending on the species. Eventually, juvenile clams fall from the fish to the stream bottom to live out their lives.
Photo Source: Fisheries, Vol 19, No. 9, Sept 1993.