Why are corals colorful?

[thamnasteroid]

There are fish who have spots to look like an extra pair of eyes by the rear fin. Just because it’s “non functional” doesn’t mean it’s purpose is not to deter predators.

Whose to say that some corals use bright colors as a means to appear toxic

And I do understand the pigment is a means for if sunscreen and has other purposes as well.

This is all open conversation and I enjoy throwing another viewpoint out there. I could be wrong it’s all theor…err…hypothesis ;)

If corals were to use bright colors to appear toxic, some corals would have to be toxic and colorful in the first place in order for other corals to evolutionary want to imitate their colors. As far as I know, there are no brightly-colored Scleractinians that use toxins to deter predators. Color would have to be found throughout a whole species, not just in some populations, and be maintained no matter what environment it is found in order for the toxin hypothesis to make sense. We know what coral pigments are for, because we have studied them and what they do.