What is this white spot?

[briansmyth]

Lawnmower blenny has a white `growth' on the the edge of its mouth - no other white spots. My first reaction was cotton mouth and not ick;thought I'd get your thougths since this might be quicker than the researching I will begin now..

[shawn lipon]

cold sore!!!

[briansmyth]

Funny you should mention that ... I've had a challenge keeping the temperature in the tank consistent - often there is a two degree difference over the course of a day and I understand that it should only be one degree.

I have a six line wrasse who occasionally gets white stuff on his head or his sides - he must pick this up from mushrooms or other coral and these white things comes off - am hoping this is the case for the blenny, too.