Help with ID: What is it?

[Rippin]

Hi all,

Just starting up a tank and received some live rock. I noticed that it has this white stuff on one of the rocks. Is it a sponge? fungus? Is it dead? Should I remove it?

It is outlined in red in the pictures below (one with, one without the flash).

Thanks in advance.

http://members.shaw.ca/nemod/aquarium/id01.jpg

http://members.shaw.ca/nemod/aquarium/id02.jpg

[Bob I]

It is really out of focus, but even so, my guess would be sponge, and I would not worry about it.:mrgreen:

[Farrmanchu]

It's sponge, might turn blueish. I had a nice yellow one grow outa nowhere, something ate it.

[Rippin]

Ok, thanks.

But aren't sponges not to be removed out of water? When I was transporting this rock, I'm sure it was out of water several times. Shouldn't it be dead because of that? What color does dead sponges turn to?

[albert_dao]

Some sponges are more resilient than others.