Thanks, Colin & Andy. Admittedly the photo lacks resolution. It was a 5.5 MB file that I shrank waaaay down on the laptop. BTW, Colin, thanks again for telling me Windows includes a nice photo editing system. Much appreciated!
I went with the top 5 Oscar diseases in researching this & cotton wool was the best fit, but incorrect. This is not my fish. My fish are asymptomatic, but I am always so grateful to learn more & pass information along to another who may benefit.