How do sea otters avoid breaking their teeth?
Environmental writer Isabelle Groc answers your wild questions.
Sea otters - which inhabit the shallow coastal waters of the northern Pacific - are renowned for preying on hard-shelled marine invertebrates, including abalones, sea urchins, clams, mussels and crabs, usually fracturing the shells with their teeth.
A recent study has revealed that sea otter tooth enamel is much tougher than that of humans, helping to prevent their teeth from being chipped when cracking into the prey using their high bite force. The animal's enamel contains additional layers of a protein-rich gel that works to prevent cracks from spreading.
However, when tackling species with the heaviest armour, such as as marine snails and thick-shelled bivalves, sea otters often employ tools. They typically use a rock as an anvil and repeatedly bash their prey against it until the shell cracks open, then extract the meat from the shell with their canines.
Indeed, research suggests that the sea otter's bite force may not be sufficient to open the hardest-shelled prey items, hence their use of tools. In fact, sea otters are one of the only mammals (apart from primates) to have developed tool use.