[Zapins]

Are you sure it isn't a "key-hole cichlid"? sorry!

I am a bit suspicious that it is a disease since diseases take a while to chew through tissue, usually damage is the culprit if the injury suddenly appeared. Can you post a picture? Do you have a puffer fish in the tank?

 

[Zapins]

Wow... is that hole clean through him or just on one side??

Looks like a puffer bite to me. They take chunks out of everything! But if you don't have any puffers or other vicious fish then its a mystery.

 

[Zapins]

That is amazing!

I think there is a good chance it will make it if it is an injury. I once went spear fishing and shot at a fish. The spear pierced him in 2 places but it was able to tear free and escape. Its wounds looked fatal, but lo and behold 3 days later I came back to the same area and I saw it swimming around perfectly fine with the huge wounds starting to heal.

 

[Zapins]

Probably either cataracts from old age (it is 6 yrs old) or camera flash.