Fuzzy white... sponge?

[ajohns20]

I would greatly appreciate any help I can get on IDing these new white growths on my live rock. I've been scouring the internet for hours and I can't find anything that seems to fit. At first I was afraid that it was aiptasia but they are attached directly to the rock and are not on a stem of any kind. Is this a sponge? A fungus? Some type of worm? I just want to know if I should be figuring out how to get this out of my tank or not. Any help or suggestions are greatly appreciated!

 

[tektite]

They look a lot like the white/clear sponges I have growing in my tank. Here's a pic of one of mine, a little less skinny than yours but looks similar in structure:

 

[cbrownfish]

Sponge species. Good to have, harmless filter feeder. There are thousands of sponges....don't stress yourself out too bad trying to find the exact species.

 

[partypalooza5]

I have/had em too, but all of a sudden almost all disappeared... weird.

 

[GrendelPrime]

i have them growing in my zoas..sooner or later they should disapear

 

[Reefmack]

Don't be too sure they'll disappear. Some can grow over and smother out zoas.

 

[GrendelPrime]

in the case of them starting to over grow zoas what would be the best way to remove them?

 

[ReeferMan420]

I would leave them be...they are great filter feeders...like 5lbs extra live rock great. The species of sponges that will out compete other coral colonie are very rare and conditions must be perfect. I would let them stay and enjoy your extra filtration system

 

[cindyp]

Don't be too sure they'll disappear. Some can grow over and smother out zoas.

a Big +1 on that I had them smother a very nice zoa colony. yesterday I did
my best to remove it from the zoa and all I ended up with is a 5 polyp frag that is sponge free.

 

[ajohns20]

Thank you guys for all the info! I was hoping it was just a sponge, but I couldn't find any pictures online of anything that looked similar enough to convince me of it. Tektite, the sponges in my tank are starting to look more are more like the picture you posted, so thank you!

I've also begun to see pineapple sponges popping up everywhere. I don't have any corals yet but I'm planning on adding some mushrooms and zoas soon at the very least, so hopefully the sponges won't do any damage. They have been growing and covering more rock, but seem to be more interested in growing thicker tentacle-type things than really spreading to cover all of my rock. Here's hoping they wont bother any future corals I add!