Please ID (sponge? coral?)

[c_scherer123]

I have no real way to describe this. It is about an inch round, oval shape. Last time I thoroughly inspected the live rock was about 3 weeks and it wasn't there, that particular rock has been in my tank since April. It is in a very shady spot.
It seems to be uniformly attached to the rock (ie no clear base like aiptasia) and doesn't seem to react to touch, movement, or light change.
This particular rock has had problems with hair algae, though the other rocks are fine, don't mind it...
I find it really pretty, and if it isn't an unwanted pest, I wouldn't mind a few more. If it could reach 5-6" wide I think it would an awesome sight.
Can anyone ID it?
link to a larger/clearer picture: http://i445.photobucket.com/albums/qq176/c_scherer123/aquarium/Saltwater/unknown1.jpg

 

[AJSTITAN14]

Maybe a q-tip sponge?

 

[Micromussa]

looks like a Sponge, they may dissapear from your tank as quickly s it appeared, or grow

 

[kevantheman35]

if it reacts its not a sponge looks like some kind of crazy feather duster like worm

 

[iamwhatiam52]

Tunicate?

 

[c_scherer123]

It doesn't look like any of the Tunicate pictures I found in searching google and other places. It looks kind of feathery.
I thought it was an odd manjano until I got a closer look.

 

[jollyballs]

bump

 

[Josh72836G]

I'm pretty sure it's a colonial tunicate. I'm not sure what their success rate in aquariums is though.

 

[rowjimmy]

+1^^^ Colonial tunicate colony.

 

[tatuvaaj]

+1^^^ colonial tunicate colony.

+2