Sea Anemone

Sea anemones provide clownfish protection from predators through their defensive arsenal of stinging tentacles - few species dare approach. In return, anemones benefit from clownfish services: defense against anemone-eating species, parasite removal, and improved respiration from water circulation. The anemone's tissues also host photosynthetic zooxanthellae that receive nitrogen compounds from clownfish waste.

The anemone's stinging cells fire indiscriminately at most fish, yet clownfish move through them as if through open water. This protection-service exchange exemplifies mutualism where neither partner dominates; both flourish.