White "stuff" on clownfish mouth.

[Rondelet]

Don't forget that any fish, like the damsels, or inverts, such as LPS, can act as carriers - bringing pathogens into your system without showing signs of disease. Now that I've thought about it, it's possible that the clown ran into something or was in a fight and the white stuff is simply excess mucous and part of a skin healing episode. Whatever the reason, the good news is that it's going away!

[untamed]

I had something similar with my clown recently. To me, it looked like he stuck his nose into something that he shouldn't have. For a few days, he had white marks all around his nose.

A few days later, all the damaged scales fell off and he looked fine again.

[Railskinner]

Ive just added another clown to my tank a week ago and they seemed to have being fighting quite alot ,looks as though they have settled down . Today i noticed as well that they have white lips. I now think this is bruising from all the bitings that they were doing to each other. I'm going to have to watch this as well carefully. Also are eating very well.If u discovered what this is plz let us Know