both my oscars have a lump under their jaw line.now i was lead tobeleve this is common when they are gettin ready to breed from the rubbin they do against the rook that they clean for the eggs?i must say every pair of oscars i saw had them but is this right and if not what should i be doin?

very common, don't worry

I had a Jack Dempsey that lived for many years with a similar lump. It never posed a problem.

I had a Jack Dempsey that lived for many years with a similar lump. It never posed a problem.

I reckon these lumps are like a callus. They get them from constantly brushing up against the edge of the tank or from cleaning rocks. Im not 100% sure that is the cause tho. However whatever the cause is, as oscarfishlover says, it is very common and nothing to worry about