This is white and every aiptasia picture I have seen makes them look brownish. Is it aiptasia? Either way, it will be gone in a few minutes.
I may have totally screwed myself if it is, because I was removing a bubble algae ball and this was hiding beneath it. I poked it hard with the pointy tool I was using before I saw it. Will it have squirted out "babies", or is it too small? It's tiny on this frag of daisy polyps.