Help ID this structure

[Dustoff79]

DSCN3655.jpgCan anyone explain to me this structure in my Zoa? DSCN3653.jpg I have a large two prong structure on my green Zoa and a small one beginning in my red. I have no clue as to what it is. Any help?

DSCN3652.jpg

[tebstan]

Looks like sponge.

Unless... theres ever a worm pokin out. There are some vermetid type critters that can create red tubes. But those red zoas have a greenish tube... so I'm thinking sponge.

agitate the zoas some, see if the growth continues down around the zoa matt, and you'll know if its sponge.

[tebstan]

Here's a top down shot of my pink sponge growing in zoas. From the side it looks just like your pics--all you see is a few tubes poking out

[Dustoff79]

So is this OK. What impact does it have? will it compete or damage my Zoas? What can I expect? Sorry, I know nothing on sponges and not much on the web.

[tebstan]

Sponges are good, they're natural filter feeders. I haven't had any problems with my zoas around the pink sponge. I'm usually more worried about the sponge itself getting damaged when I move rock or frag zoas. The zoas growth has not been impeded at all.

I love sponge growth, I've got lots of different kinds. But no green tube stuff yet, that one's pretty cool.