The amazing part comes in HOW a female mussel can get her larvae on to a highly mobile fish! Click HERE for photos and videos of how mussels go fishing.
Photos of glochidia:
These larval mussels are tiny, with most species ranging from 150-300 microns across. That is barely visible to the naked eye! But they have shells just like their parents and come in a range of shapes from rounded to more elongate or triangular. The only way to really get a good look at them is through a microscope.
Some glochidia like from the Creeper (Strophitus undulatus) or the Eastern Floater (Pyganodon cataracta) have teeth to help them hold to fins as well as to gill tissue.
Yates Mill Aquatic Conservation Center at NC State University 