They are so interesting and beautiful, it's hard to resist. Note its shell patterns and long foot as you pull the mussel from the stream bottom. Actually, mussels do not have a head. The mussel walks through the substrate with its foot. A mussel in place on the stream bottom works like a vaccum cleaner drawing water in through its incurrent siphon, filtering out food and cantaminants, then excreting wastes that become part of the food chain.
Researchers use water scopes to locate mussels.
When replacing the mussel, rebury the foot end. If you accidentally rebury the siphon end, instead, you could suffocate the mussel. If unsure, leave the mussel close by in the same habitat, on its side, behind a boulder or in quiet water and let it rebury itself. If left unburied in swift current, it can easily be swept away to unfavorable habitat. Be sure to always put mussels back where you found them.