Blue sponge ID please

[fessoclown]

I got a big chalice from a friend but the rock it came on had aiptasia so I chiseled it off. In doing so I discovered this blue sponge inside the rock. I saved the bits because it looked cool.
Can I get an ID please? Should i keep it?
thanks!
https://lh3.googleusercontent.com/-14EhQbwbBIU/VGv-nX5RWBI/AAAAAAAACP0/et3PLdH9gmE/w510-h680-no/IMG_20141118_211033.jpg
https://lh6.googleusercontent.com/-M0_84cyF16k/VGv-l2gybwI/AAAAAAAACPo/TqG4v6B3yME/w510-h680-no/IMG_20141118_211042.jpg

[billdogg]

You are correct. It looks like a blue sponge to me too��. I vote for keep it and see how it does. I would put it several different location to see where it will do best.

FWIW IME, sponges are benificial filter feeders.

[Lavoisier]

Probably should turn the rock upside down and move sponge out of light.

[fessoclown]

Probably should turn the rock upside down and move sponge out of light.

ya, I just put it there to take some pictures. I will place it all around in shady places.

[cloak]

Are you sure those aren't just pieces of a dead coral? They look extremely similar to the skeleton I busted up to attach frags to. There's a piece in the photograph below. It's blue like yours. In the picture with the books, you can see where I got it from to the far right.

http://i172.photobucket.com/albums/w16/jAb83_2007/jokers_zps3a9b641d.jpg (http://s172.photobucket.com/user/jAb83_2007/media/jokers_zps3a9b641d.jpg.html)

http://i172.photobucket.com/albums/w16/jAb83_2007/books1_zps6d7ba0ce.jpg (http://s172.photobucket.com/user/jAb83_2007/media/books1_zps6d7ba0ce.jpg.html)