What caused this damage to Monti cap?

[Lake75]

I have a small frag of orange monti cap. It's been in my tank for 2 and a half months and has doubled its size. Then this morning I found that it became like this:

I'm not entirely sure if it's OK last night because I didn't pay attention to it, but I'm positive that it was good in the morning. So, what could cause such a massive damage overnight? Does it still have a chance?

Thanks!

 

[zedman]

Hey lake 75 had the same thing happen, did you notice any change in color in the days preceding the death? Not sure why mine died but it is in my 12g nano and I might have gotten replacement water pourd on it by accident.

Zed

 

[Lake75]

No, I didn't see any change in color before this happened. I have another small frag of purple edge monti cap sitting close to where this guy was and it hasn't shown any signs of problem.

 

[rleechb]

Doesn't look like any sort of predating/pest you have there. Looks like RTN.. which should be caused by water quality issues. The fact that the other cap hasn't rtn'd doens't necessarily mean that it's not stressed out, or won't. I've had issues with water quality before (huge dip in alk) where one or two sps stn/rtn, but everything else in the tank seems fine.