What is this on my snail?

What is this on my snail? *Update: It's a Coral*

One of our astrea snails has a neat-o hitchhiker on him. Anyone care to figure it out? I'm guessing it's a coral and not a dead one at that. The "polyps" were open, but as I tried to turn him for the second shot, I accidentally touched them and they closed up. Any help would be much appreciated! ;D

Open:


Closed:


Better Pic Open:

 

do those little circles extend out like individual little flowers? it's pretty cool and tiny!!!

 

They stick out like little flowers. I think it's awesome! Here's a pic with better color, but the polyps are closed at the moment.

 

looks like the beginnings of a finger leather to me. when you touched it was it hard like a shell?

 

Yes, it was rough and hard

 

oh ok then that rules out finger leather, those kinda feel like firm, not hard, like a finger, without the bone(kinda) Then I'm gonna say and acro or monti(?) of some sort. You might just have to wait to see if grow more before you can tell what it is. I'm sure someone else will tell you. Do you have mh's?

 

We're running a Current USA PC Sunpaq 10,000K/460nm. It's been on there for atleast 2 weeks since that's when we introduced the astreas.

here's one with it open:

 

I am so undecided as to what it is. Looking at each polyp and it's pattern looks almost like a brain, but it's way too small, but then it looks like a f.l., but you say it's hard and rough and f.l.'s are hard or rough. Acros/brains/most montis won't grow under pc's, back to f.l. hmmmmm..... I'm sure someone will chime in soon. All I can say right now is I'll help keep this thread alive until you get a good answer. I'd like to know too.

 

I have posted pictures of this in the past and no one could really figure it out. But it looks just like yours but bigger.

 

I thoroughly appreciate all of your help. Google images is running on overdrive due to me! Muahahahaha!!