Mussel, which is the homonym for muscle, actually comes from the same root, the Latin word for - you guessed it - muscles!

Mussels are golden bivalves with black shells that people can eat. You find them clinging to rocks near the shore or in the bed of some rivers.

Did I try and slip 'bivalve' past you? Uh, sorry! Bivalves are marine animals with hinged shells. Some have digging feet, like clams. Some can swim, like scallops. Some attach to surfaces, like mussels.