White fuzz on Zoo's Rock

Hello all, about a week and 1/2 ago maybe I purchased an awesome Zoo rock from my LFS (Avatar) I noticed after placing it in my tank that it has a patch of white fuzzy stuff growing on the back side...anyone have any idea what it is, should I be concerned? Been really lucky with not having many unwanted things end up in my tank, hope my luck hasn't ran out! Check out the pics and let me know what you think! Thanks!

 

Could be die off, my tonga branch had some. Looked just like it.

Have you checked your tank levels?

 

Could be a sponge...hard to tell

 

Checked today, good & stable...should I go ahead and remove it as a precaution? Can I lift the rock out of the water to do so, how would I go about doing that?

 

I was taught by a marine biologist to smell things that are growing and that is a ? He said if it smells bad then it's bad. I have the same fuzzy thing on my rock and never grew. I left it and nothing has happen. Who knows?

 

I'm with Bruce on this one. It's most likely a sponge. Just keep an eye on it and make sure that it doesn't start growing over the zooanthids.

 

I would say it looks like a sponge or a tunicate. Does it have a opening in it like a mouth? 8)