Never thought he could survive (Warning, image may be disturbing)

Found this bifas stripped to bone in the morning and thought that he wouldn't survive for 24 hours. I placed him in a hospital tank and he made it the next day, then 48 hours, and a week later he started to eat. He survived! He is a young fish so do you think he has a chance to grow back skin and flesh to cover the bone. If he is permanently disfigured, I may consider euthanizing him.

I just placed him in clean water, with no salt or any disinfectants. I didn't expect him to live beyond 24 hours as I had fish died with less injury. The exposed flesh looks like white fillet on a dinner plate. It's been 2 weeks and he shows no sign of infection. He is handicapped from swimming normally, but is otherwise active and eats eargerly. Initial injury has skin and loose flesh hanging on which fell off in a few days exposing the white fillet. It's amazing this little guy survived.

I did not see the attack, but suspect a 9" melanuras did it. The injured bifas is 4", and was raised in a 75 gal with the melanuras among other smaller fish. The melanuras is very docile, and shows no aggression towards any fish. But if the melanuras decides to attack someone, he is big and powerful and won't take much to do serious injury to a small fish in a small tank.