Sponge? Closed Anenome? Or something else? (Pic)

[EastMr2]

I'm new to this, so I really have no clue.
Picture isn't great quality, but it seems to have a brown outer layer, and then like a purplish top layer that balloned up when I put it in my tank.

I have a new tank that hasn't cycled yet.
I just got this with my live rock.
I first thought it was a sponge so i didn't put it in the tank right away, but then it seemed to move some, and I was under the impression that sponges die when they come in contact with air, so i thought it might be something i want to keep so i put it in the tank, and will hope it survies.

If anyone can identify it that would be great.
Thanks!

 

[Anonymous]

From that picture this critter looks like it would be of the Phylum: Cnidaria (Anemone).
Impossible to tell from the picture the genus or species. Survivability would depend on how well your skimmer and water changes keep your Nitrate and Ammonia levels to a minimum during the tanks cycle.

Regards,
David Mohr