I have had him for a very long time, I feed him often with krill, and shrimp. There has been enough iodine in the water, and other elements as well. For some reason, in these last 2 weeks, he has gotten angry. It is the weirdest thing. He is going around eating the corals. His favorite is the frogspawn. He keeps on pulling off the frogspawn arms and eating them. I started to feed him every day because I thought that his appetite went up, but that hasn't helped. My nice large frogspawn is still there, but I have no hope for recovery. It has also eaten a couple of arms off the tree coral as well. I don't understand. He has never done this since I've had him, for about 1 year. Have yall had this kind of experience?? I DID add 7 hermit crabs to the tank. It is a 75 gallon. They aren't messing with the corals at all. I see the shrimp killing the coral all the time. Could that be what is upsetting him?