Ruskull did you find out what this is? This morning I found my gold gourami to have a spot that looks exactly like this, in the exact spot (the top of his back, near his fin). LFS said probably a bacterial infection, and gave me some antibiotic meds. My other fish seem fine, but I quarentined him anyway. The only other odd thing was that he had been hiding in a corner of the tank the past few days, only coming out to eat. Not sure if he was being bullied by my blue gourami, then got stressed and sick??