Clownfish live in sea anemones, which protect the fish from predators. the sea anemone isn't harmed and doesn't benefit from this relationship. this is called parasitism commensalism phoresy mutualism

The correct answer for the blank is- Commensalism.

Commensalism can be described as a long term biological interaction between two species or two different organisms in which one species is benefited and another is neither benefited nor harmed by the association.

In the given question, clownfish is protected from predators and sea anemone is neither harmed nor protected.

Thus, this association describes commensalism.