I purchased this tang a little over two years ago. He was about the size of a half dollar and now is slightly larger than the palm of my hand. I quarantined him as I do all my fish for 6 weeks. He has always been a voracious eater, fat and happy, although somewhat shy. So shy he is a royal pain to get a picture of. I did the best I can with the two attached photos. He won't be still long enough to get a good pic. I guess that's a good sign because he is not lethargic. I feed the tank nori three times a week and LRS and Rod's one to two times a day. Occasionally I feed some mysis. About three weeks ago I noticed his slime coat was turning white and he refused to eat. It is not spots but white slime. No other fish in the tank is affected. I have several wrasse that occasionally quarrel with one another but, I've never seen any fish fighting with him. I started offering nori every day about two weeks but he still refuses to eat. His slime coat is looking worse and his spine is starting to show. There has been nothing out of the normal as far as swings in parameters or new additions to the tank. The tank is 120 gallon SPS dominate mature colonies at 5 years old as of last August and very stable. The only thing I can think of is possibly a fungus. He is the only tang in the tank. I'm not sure how I would catch him even if I knew how to treat him. I was hoping he would fight through this but, without eating I'm sure his immune system continues to weaken. Any ideas?
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