Who knew Nemo was so clever?

Actually the star of the "Finding Nemo" film was based on False Percula Clownfish. So-called True anemonefish, or clownfish, shown here off the coast of Indonesia, look very similar (clown-like, that is), and have set up an ingenious arrangement with deadly sea anemone.

The deal is this: The clownfish live within the sea anemone's poisonous tentacles. Those tentacles keep would-be predators at bay, including morays, scorpionfishes and snappers. In return, the clownfish supply the anemone with scraps of food it doesn't eat, as well as its droppings, which nourish the poisonous polyp. It also preens its hosts, removing parasites.

Only the anemonefish (and certain damselfish) can get away with this arrangement -- and it's not simple. Before taking up residence in a sea anemone, the anemonefish must first acclimate its body to the anemone's tentacles by gradually brushing them against different parts of its body. A layer of mucus over the fish's scales further protect it from potential stings.

Some researchers believe the clownfish's mucus coating may be based on sugars rather than proteins, which foils the sea anemone from realizing the fish are a potential food source.

Whatever the explanation, the small colorful fish have evolved an ingenious way to keep clear of predators. Should one come near, it can simply duck into the protective, stinging tentacles of its host -- and wait out danger.

There are 28 known species of anemonefish, most of which live in the shallow waters of the Indian Ocean, the Red Sea and the western Pacific.
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