Clownfish perform an elaborate dance with an anemone before taking up residence, gently touching its tentacles with different parts of their bodies until they are acclimated to their host.
A layer of mucus on the clownfish's skin makes it immune to the fish-eating anemone's lethal sting. In exchange for safety from predators and food scraps, the clownfish drives off intruders and preens its host, removing parasites.
There are at least 30 known species of clownfish, most of which live in the shallow waters of the Indian Ocean, the Red Sea, and the western Pacific. They are not found in the Caribbean, Mediterranean, or Atlantic Ocean.
Changing SexSurprisingly, all clownfish are born male. They have the ability to switch their sex, but will do so only to become the dominant female of a group. The change is irreversible.
Clownfish have evolved an ingenious though slimy way to use stinging anemones for their own protection.