What happened to this coral?

Last night this coral was fine. Here is an actual picture from yesterday as I was trying to work on getting a good exposure for taking more pictures. Tonight, I came home from work and there is a whole row of polyps GONE. As if something literally yanked them out. I would say probably 4 or 5 are gone, all in a straight row. I can't get a good picture because they are kind of over the top edge where a piece of rock juts out and I can't get the right angle with my tripod. Hand held is too blurry.

I have a bi-color blenny, a clown fish, and 3 peppermint shrimps in the tank. No other corals are affected. THOUGHTS???

 

What are you parameters??

 

has the rock with the colonyon it had another rock fall on it or has fallen? this may have caused tissue damage. is it a new peice maybee transport damage?
I would check if any oter polyps are decinergrating and if so cut off the bad polpys to stop the spread and then dip the rock in an Iodine solution to assist the rest
It always helps too to disclose all of your paremiters tank age and lighting and the like

 

Temp: 78
SG: 1.023
PH: 8.2
NO 2 - 0
NO 3 - 0
Ammonia - 0

That's all I have tests for.

 

You may have that Zoa/Polyp eating bug, for the life of me, I cant remember the name of it. Luna

 

Here is some more info. Tank is about 2.5 months old. Just changed lights one week ago from 14K HQI to 20K HQI (wasn't sure I liked the look of the 14K). Coral has been in there just 1 week. The LFS had just got it in the day I bought it and it appeared to have no damage. Wasn't dropped when I took it home/put it in. No rocks have dropped on it. No other polyps look damaged in any way. I tried to take a hand held (blurry) shot and have circled the white spot with the missing polyps. You see only rock and tiny holes where I assume the polyps were. Clean as a whistle! Very strange. I have never had this happen with corals before. This is a new tank for me but in the past I kept a mixed 150 gal. with both fish and soft corals for approximately 5 years and I never had a coral go from perfect one day, missing polyps the next.

 

food for thought?
sounds curious maybee you need to do a late night stake out to see if you have a hungry pest in the tank

 

I do run a moon light at night so maybe tomorrow, when I can stay up late and not impact work the next day, I can set my alarm to wake me up a few times!

 

One more thought. I also got a new Coco worm at the same time. The worm spewed stuff into the tank during the first few minutes/hour that the head was out of the tube. Could it have put something odd in the water that would affect this coral? They are right by each other. In this photo the coral is to the right a little above the worm's head.

 

You have any LPS close by, sweeper tentacles could have digested them.