I believe that my month old tiger oscar has hole in head or a fungus problem. Or could this just be a cut because he supposefully hit the top of the tank while my brother was watching tv. Pics below tell me if you need better angles. Tell me how to cure besides the me doing a 20% WC.
It's hard to tell by your picture. If it was HITH you should have noticed it starting a long time ago. Its probably a cut from hitting the lid, keep up your water changes and he should be fine.