I just caught my emerald crab yesterday munching on the last of my zoa polyps (the rest of the colony was previously consumed by hermit crabs). Going to have to get rid of this guy too!!!!
How ironic. I had just purchased an average sized frag of Xenia and a Green star polyp colony. I had the Xenia lodged into a nice spot in the rock. I kept checking on it to see how it was doing and I saw the an EMERALD picking at it. So I fight him off, I couldn't get to him where I could get him out yet. He had a death grip on the bottom of the Xenia. I finally got him off. I found another spot for the Xenia and then later last night I see the grab has ran off with him and drug him to the bottom of the rock. I again beat him off and relocated the Xenia. I tried to lure him out with some Krill and almost had him but ran out of time and had to run some errands.
The Xenia had started to open back up and had a nice spot. My wife asks "wheres that other one"? I go to point it out to her AND ITS GONE. The dang crab ran off with it. I had JUST checked on it about 5 minutes prior. I can't find it anywhere. =(