Polup shut down on SPS

[kastanzaman]

I have a frag of A. plana with 3 branches. The polyps on one of the branches have quit or minimally come out, even at night. On the base and other two branches the polyps are always out.
THe tissue on the branch also seems to be very thin and almost striated.
This (tissue and polyps started at the tip of the branch and has slowly moved towards the base over the past few weeks. I am afraid that this may eventually spread to the entire frag and i will end up losing it. Does anyone else have any experience with something like this, should i just cut of this branch to be safe?
All other corals in the tank look good.

 

[Liam]

i would cut off the affected branch well ahead of the recession and then give a dip with Seachem reefdip to both pieces,better give them a light basting in case of flatworms then discard the infected branch
How long have you had the piece?