I heard that Actinia Equina normally eats what it can catch, but this clownfish here doesn't care much about that:
https://www.youtube.com/watch?v=Ughm4mnZ1ls
Since the actinia obviously can't hold the clownfish, clownfish does whatever it wants with actinia swimming all over it. Is the clownfish having some sort of fish fun, or is there a purpose behind this playing with actinia?
It's an example of SYMBIOSIS
Clownfishes(Amphiprion ocellaris) are never found without an anemone as they have this obligate association with them. Although they can survive without them, but studies show they are much more healthier with than without.
This association is more of a survival necessity. These anemones are actually toxic and the fish is resistance to it. If being attacked they will get inside these and the attacker might be stung with this actinotoxin.
Also,
The presence of an anemone is also essential to reproduction of the fishes: their eggs are laid beneath the oral disc overhang of the anemone, where they are tended by the male.
Source:
