My Kole tang I've had for 6months or so has something strange going on with his face, it looks blotchy like color melting away, do they change colors from juvinile to adult that quick ? He is eating very well and is quite fat and happy but the whole face changing thing is questionable, all paramaters are in check and no problems with any other tank mates. Could it be from running into the rock scape, I do notice him and the sailfin doing some chasing once in a while ??
Here are a few pics that may be able to help decipher whats happening....