What in tarnation is this?

[Avi]

I've posted in Reef Discussion without any definite ID. It's kind of interesting because of the change it has recently gone through. Unfortunately I don't have a photo of what it had looked like for over a year since it came into my reef on live rock, BUT here's what it looks like now:



Up until about one week ago, it looked the same as it had since I first saw it as something growing on the live rock. It was a much darker, deeper red color and the spots on it were much dimmer, though apparent. The surface of this appeared to be smooth.

I'm not at all certain what might have prompted it to change so radically in the last week, but I did move a piece of rock above it which exposed it a little more to light than it had been. I did change over from PCs to MHs about 5 months ago and that did expose it to more brightness but that change-over had no effect on this.

In any event, now, its color had muted from the deep red to this brownish-red with green high-lights. Also, this "hair-like" appearance has become very obvious and it is growing. It was consistently about an inch and a half from top to bottom and an inch wide but it's grown a bit (maybe a 1/4 inch) for the first time since I've had it, in the last week.

It never occurred to me that this was a coral but now it has taken on some clear indications of that. The white spots, which are now much whiter than they had been all along are baffling to me. Any idea what it might be?