What's eating my Montipora?

I'm not sure what it is, but its eating my blue rim montipora!! Worms or nudis?? Anybody got a fix for it?

 

I cannot tell from the picture but it is probably nudis....if you can get it out look for egg clusters on the bottom....if it is nudis they are pretty easy to deal with if you can get all of your montis out of the tank...all you have to do is brush the undersides of all of them and look for eggs and brush them....they come off really easy...I had one friend who had a waterpic, the oral hygiene device, and used it with saltwater to blast them clear....do that 2 or 3 times a few days apart ant they should be gone....

Good luck with them....