Sponge? Am I growing a sponge in my tank?

[Rothrosh]

I have a spong-like whitish glob of something growing on my live rock. Is it actually a sponge or ?!?!?!?

If anyone has seen anything like it, please let me know. It is definately growing and spreading to neighboring rocks, just not sure what it is.

IMG00027-20100320-1142[1] on Flickr - Photo Sharing!

 

[Bige]

Looks like sponge and aiptasia down front. The sponge is harmless and filter feeds.

 

[Mitchell0605]

Looks like a sponge. The things to the right of it is Aiptasia. Your gonna wanna get rid of them. Use Kalkwasser squirted from a syringe on to the oral disk.

 

[melosu58]

My work wont allow me to bring the pic up but if it is a sponge as mentioned earlier they are harmless filter feeder.