Some kinda sponge?

[lovethemfish]

Just wondering if anyone had any info on the sponge in this picture. The greyish stringy mass in the middle. This picture is months ago too and it is abouttwice this size now. maybe 10 inches across at least. Also it is in a very dark cave part of the tank. Any info or thoughts would be interesting. thanks.Attachment 221469

 

[spanko]

Is a Poriferan sp. a sponge. Probably not going to get a species identification just from a picture. Is a filter feeding organism, good for the tank. They grow in cryptic zones as described here by Steve Tyree;
"The second is Cryptic and applies to the oft-called "twilight" zone of a reef, deep within caves or beneath the reef platform in shallow water. Incidental light is far too weak to support photosynthetic life forms."
So your description of where it is growing is very appropriate in this case.