Clownfish

The orange fish that lives in a stinging flower

The clownfish (Nemo!) lives inside a sea anemone — a creature that looks like a flower and stings other fish, but not the clownfish. The fish has special mucus on its skin. In return it cleans and protects the anemone — they're friends! The biggest fish in the family is the mother.

The clownfish (Amphiprion ocellaris) lives on coral reefs of the Indian and Pacific Oceans. It has a mutualism (a partnership that benefits both) with the sea anemone: the anemone's stinging cells don't affect the fish's mucus layer; the fish hides from predators in the anemone, cleans it of parasites and aerates the water. All clownfish are born male; the largest in a group becomes female (protandrous hermaphroditism) — if she dies, the next male turns female. The father guards the eggs and fans them with his fins. Ocean warming and acidification are killing coral reefs — and with them the clownfish's home.

Fun facts

• All clownfish are born male — the biggest becomes female.
• The anemone stings other fish but not the clownfish — they're friends.
• The father guards the eggs and fans them with his fins.