Problem with my percula

[Makana]

I've had the same percula since my tank finished cycling in the beginning of July 2004. The other day I decided to get a mate/friend for it. One of my LFS that usually stocks them was out for over a week and on my third trip back they finally had a few to choose from but not as many as normally. Anyway I got one, but it was a bit smaller,. They seemed to get along but I did notic some agression from the older one, this was only at first and then Ithey seemed happy. After 3 days the new fish died without any noticeable signs of sickness or stress (to me). I don't know what it was, everything seemed very healthy before its death. When I scooped it out it was a little nipped and one eye was eaten or taken (it was missing) and my original percula's mouth was light orange, popping out and could not close it all the was. I was worried, but it was still eating so I hoped it would pull through. A few days later it died. I;m attaching some images so hopefully someone can tell me what happened. First here's the picture of the original percula befor, when it looked normal. The bottom two are after its wierd condition appeared.

 

thanks in advance!