Symbiosis
An example of mutual symbiosis is the relationship between clownfish that live among the tentacles of tropical sea anemones. The clownfish protects the anemone from other fish.  Clownfish waste excreted provides vital nutrients, and they can boost their hosts’ oxygen supplies at night too.  The stinging tentacles of the anemone protect the anemone fish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.