The young of these North American freshwater muscles go through a parasitic stage, during which they must live attached to the gills of a Large Mouth Bass. How do they get there? The muscles have a flap that mimics the small fish that are prey of the Bass. The mimics are amazingly detailed! When the Bass strikes at it, the muscle shoots its young into the fish's mouth, where they will attach themselves to the gills until they are fully formed. Then the baby muscles drop off and grow up on the stream bed.
Here is a short video about it:
How awesome is that?? Creation is way cool, right?