Bacteria/Fungus on GSP?

[rockbassray]

Friend of mine has a GSP and when it was first boguht the top of his mouth had a slight brown color to it.. and seemed fine for about 3 months.. Just recently i came to the tank one day and we noticed that part of his upper lip was missing.. some people said he might have bit a rock by mistake when eating. I havent found any information anywhere regarding what this color may be, but it seems to more then just color. i am thinking it may be some sort of mouth fungus or something. anyone ever seen this before? and is there any hope?

[manutius]

This post has been started in the hospital section I believe