Otters hold mussels so as to orient the flat sides of the mussels against the “palms” of the paws and the seam of the two shells contacts the stone in a pounding instance. Mussels are pounded against rock or stones at a rate of two pounds per second. It takes approximately 35 blows to crack open a mussel.

Do otters smash clams?

They’re the only marine mammal that uses stone tools and rocks to break open shells. Sea otters have been known to crack open shells on their chests using rocks as they float on their backs, but they’ve also been observed using rocks along the shoreline as “anvils” to crack open mussels, clams and crabs.

How does a mother sea otter open a clam?

When they catch a large clam with a hard shell, they have to use a tool: a flat stone on their belly to smash open the shell.