These are very deliberate feeders and hard to get to eat. A lot do not accept prepaired foods and end up starving to death. What are you currently feeding this fish? In my experience, they do not accept flake food. The best thing to do is feed froozen brine that have been thawed out in a garlic soultion like Garlic Guard by SeaChem or Kent's Garlic Extreme. THis will hopefully stimulate the appitite of the fish. Do you know where and how this fish was caught? I would contact the LFS
where you got and ask them how long they had it, if it ate for them and what they fed it.