Hi there and hope all is well,
Could be something could be nothing but thought it was best to ask advice anyway. I have been looking at my oscar called Asbo over the last few days and when he breathes as he come to the front of the tank for attention at the top of his top lip he seems to breath and there is a mucus there well kind of mucus, its not hugely packed but it seems like a covering and when hes breathing it tends to come out of his mouth a little, dare sat thats with the inhale exhale ect. Hang on off to look at at it again,
hmmmm i have had tropical fish before and to me it looks like a bit of fungus starting to build, i could be wrong but i am sure this was not there before. I have only had him a month and have noticed over the last few days he aint eating as good, found a shrimp and half muscle wasted at base of the tank and that was in the morning when he should be real hungry.
He wont wouch cockle now either.
Hope you can advise as kind of worried here, even on treatment ect i am in the uk so cant get any american remedies ect.
Await your reply and many thanks in advance

cheers
H