I really hope it is something that will heal. I'm just concerned that if it was not an injury caused by another tankmate or fallen rock there would be some underlying cause that needs to be treated for the fish to recover. The injury seems to symmetrical to be a gash or wound in my opinion. It seems like some sort of "invisible thing" is eating away at him in an outward pattern or something. Oh well, I'll keep searching for marine fish diseases and see if I come up with something that matches. Some of the stuff I've come across is pretty gross!

Thanks again for all your input.