I had 2 large aiptasia and about 6 small ones that came on the first piece of live rock in my tank. They were spreading pretty quickly before I introduced one Peppermint Shrimp. Within two days he's wiped all the Aiptasia out except for one which is still hanging on (although 1/4 of the size it used to be). I'm hoping he takes that one out too. As for the polyps, I've got soem Anthelia that I recieved with a kit and the peppermint shrimp hasn't bothered them at all.
Dew