I have noticed instead of healing they tend to grow out of chunks like that. It sometimes can take a long time, as Im guessing that one will because it looks to be pretty big.
In general I have noticed ray wounds close up quick, but missing sections take a while to regrow.
I don't doubt it either, was just curious. It is a big chunk, about the width of a quarter and about and inch long. I have my fingers crossed that maybe they spawned when this happened.
Colin at the time of her getting that wound, my old male just died, and I noticed that in the area there was some dead tissue, then with here moving constanly it just fell out. She was by herself when I noticed it.
Then I got the new ray from Dave and the only thing we could come to the conclusion was that my old male did it.
The catfish I have in the first pic I just put back in the tank yesterday and he has been in there before and if he took a bite it would be bigger that what it is. In person the wound looks just like a ray took the chunk out.