The clownfish shelters among the toxic tentacles of the sea anemone, gaining protection from predators, while also finding feeding opportunities around the anemone.
A special mucus layer on the clownfish's body protects it from the anemone's stinging cells; this obligatory symbiotic relationship benefits not only the fish but also the anemone.
The clownfish contributes to the anemone's nutrition by releasing food particles into the water and actively defends the anemone from predators like butterflyfish, strengthening their partnership through protection.
Once considered commensalism (one-sided benefit), this relationship is now recognized as mutualism (a mutually beneficial partnership).