Zoa eating nudi. Might want to remove those zoas. And dose flatworm exit to the tank asap to get rid of any that may have already drop off before they lay eggs. Life cycle is fast so get on it.
Hopefully you pulled this frag immediately out of your tank. If I find a frag with Zoe eating nudibranches on it, I throw the frag in the trash...not worth it to put it in your tank...the eggs are hard to find and its not worth the risk IMO...you could however also put it in a quarantine tank by itself for 3 months and monitor it
Honestly the frag was a bonus the Rock is in a fowlr qt tank. I didn't see the replies til I was at work today. I may still pull the drag and cleanse then move to my reef tank.