Right Valve

Left Valve

Mussels are part of a group of mollusks called BIVALVES because they each half of a shell is called a valve. Thus, because mussels have two valves they are bivalves! Though each valve is essentially a mirror image of itself, some of the internal features are slightly different between the right and left valves.

Lateral teeth

Depending on the species, some mussels have what are called ‘lateral teeth’, which lock together in conjunction with a hinge ligament to aid the mussel in opening and closing. The left valve typically will have two lateral teeth running parallel to one another, whereas the right valve will have a single lateral tooth that fits between the teeth of the left valve.