I have had a nice group of Duncans for a couple years now (Thanks, Todd!). Spilt them a couple times, gave some away, just a nice coral that I seemed not to be able to kill.
So, it was disturbing to say the least, when i returned from a two week trip to Yellowstone to find the small colony in my small tank suddenly gone. Like 9 out of 10 heads dead.
I haven't been able to pinpoint a problem. Parameters have been good. I had folks tend to the tank while I was gone. And they even fed the corals Oyster Feast once a week. I figured it was just one of those mysteries. Until today, when I noticed something tiny and green under some rock work. I fished it out to discover it was a Duncan head unattached to anything else. It had floated into a dark corner, and so was quite closed up. I just through it (and the SEVEN others I found after really searching) on top of the reef rock, and within an hour, they were all quite extended, a few pushing an inch in diameter!
So, what gives?
Did these just detach from the colony to float away in hopes of a better location? To start a new colony? Could a fish pulled them off? A hermit crab? I have never seen anything like this one, so I'd love to hear some insight into the reasons.
Polyp bail out...I have seen it a few times. I would say it is a form of self preservation and the result of unhappy conditions. Is it possible that your tank may have gotten too warm? Bad water quality is another possible culprit...corals require so little direct feeding, I wouldn't leave oyster feast in the hands of the untrained. Again, hard to say what upset them...but probably worth a good water test to see if anything is out of whack and a nice water and carbon change as a precaution regardless of the water test.
As for the loose duncans, I would leave them alone if they seem "happy" now. The chance long term that they will make it is low IME. But if conditions improve and stay consistent, they may attach and start to regrow.
More importantly, where are the vacation (fish) pics?
Params all seem good, with my testing ability, but I will take a sample to the LFS for further confirmation. That tank probably did better temp-wise then the one at home where the Duncans are fine. But ya never know.