You had one on a rock that you got off the auction at frag swap ,my guess is there was eggs or you didnt get all the little suckers . i would inspect your tank well with a flash light ,you may find more then you think
try to use 2 buckets ,,one for dipping one for rinsing the coral off ,use water from your tank( ,this will get you a water change too )
Your most important task will be looking for the eggs ,they will look like this pic i posted ,those will evenually catch and youll have to thru this again
they are in a spiral shape ,very easy to look for when you see one
That looks like Berghia nudibranch, they are coral safe. One way to tell is to stir the little bugger around & see if the bristles come off. The one you have looks strong & well fed from it?s color. Not positive & wouldn?t risk it but the below links should help you identify. The best time to find them is in the middle of the night w/ a flashlight in-between the wholes in your rock.
exactly. this this is eating as it looks healthy. also the pics of the zoos you posted asking if the white specks were eggs. looks like a few are missing the crowns or tops. this nudi was doing the same to my zoos.