That picture is funny!!! I have a PT & he sometimes gets a white appearence on his "lips" or mouth. As long as it doesn't look fuzzy or fungus like he should be fine. My pt gets it from picking or grazing along the rocks for food!! If it's a fungus or "cotton mouth" it's gonna be tough to get rid of. I beleive that it is a viral infecton. As with all VI time is pretty much the thing that heals. (although over 15 years ago I had a orange shoulder tang that had cotton mouth) I got the fish from my Dad after he broke his tank down. I figured he got the infection when he was fed frozen food that was thawed & refrozen. (due to being left out for a day by accident) It wasn't me who did that!!!! The only way to remedy it from the OST was to phisically rip it off it's mouth & dap a bit of iodine on the effected wound. (it was a nasty event...let me tell you!!!) Pretty much had to net the fish & wrap him in a clean bath towel to do the event!! (while one person held the fish another ripped off the cotton growth) I was the one who held the fish but it was still nasty to experience & the growth had an awful smell!!!!!
HTH,
B
PS. the fish healed up nice from the surgery & the growth never came back. (It was actually there for 6 + months before I decided it wasn't going to go away & decided to give it a yank)