Clown fish can swim among the poisonous tentacles of sea anemones without being harmed. The sea anemone protects the clown fish from predators, but gets nothing in return. This is an example of .

Commensalism is a relationship in which one organism benefits and the other is neither helped nor harmed. The clown fish gains protection from predators, while the sea anemone gets nothing in return, so this is commensalism.

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