Problem with keyhole limpet

[basiab]

I had a beautiful coral, red with blue center. Not sure what it was, maybe a blasto but I don't think so. It was flat and a bit larger than a quarter. Even had a couple babies starting to grow underneath it. It got attacked by a keyhole limpet. Not sure why siince they only eat algae. But I saw it on the coral and removed it. There was about 1/3 of it left. It grew back and then I came home one day and it was just skeleton and the limpet was right next to it. It does not bother any other corals that I have.