Clown Breathing Rapidly

[b.branscombe]

One of the TR Percula Clowns I picked up has separated himself from his buddy and has found a piece of rock to hang out in with virtually no flow. He's constantly opening and closing his mouth, it looks as if he's talking underwater. He's not too interested in eating either. Any suggestions?

 

[b.branscombe]

Ok, so as far as I can tell, the clown is dead. He hadn't left his perch for three or four days, and when I went down today to check the tank he was gone. I've looked everywhere and I can't find him. It's a 220g tank with a lot of hiding places mind you, but he was a tiny fish with a lot of things in the tank that would relish a corpse, so I wouldn't be surprised if he disappeared without a trace. If I encounter this in the future is there anything I can do preventively?