What is this fluorescent growth on my live rock?

[Jonify]

Setting up a new frag tank, grabbed some live rock from my LFS today. I asked them to confirm that no fish or coral was kept in the holding tank, they confirmed. So, what the heck is this!? it's much more fluorescent in real life than this photo (sorry about that).

 

[Casket_Case]

No idea, but it’s beautiful

 

[Jonify]

No idea, but it’s beautiful

I have never seen something like this ... according to google, there are lots of possibilities, including Coraline that is declining in health because of over-lighting (but the holding tank I got the rock from wasn't lit at all).

 

[Jonify]

It was dying Coraline. Two days later, it's all gone. Some Coraline become fluorescent when they die, which can sometimes happen with exposure to air. I assume the parts that were fluorescent were the parts that were not entirely covered in damp paper towels.

 

[HB AL]

I was gonna say that when I've seen this its coraline and within a couple days the neon zones will be dead coraline.