Clownfish have a protective mucous coating over their bodies. This coating protects them from getting stung by the anemone's venemous sting. This makes the relationship between clownfish and anemones a unique one: not only do they both provide protection against predators for each other, but the anemones provide a home for the clownfish and the clownfish provide leftover food for the anemones to eat.
Large fish, eels and sharks can harm the clownfish. However, we shouldn't worry too much because most can be protected by the anemone's tentacles.
