I think this is going to become something cool.

I've been watching it form in a dark spot for a week or so now. It started out as just a white, dome-shaped protrusion. Now it's sprouting something. It might be half the diameter of a pencil now.

 

Looks like a filter feeder I get small ones all over the place, they look like a cocoon with fingers sticking out the end, the name escapes me though...

 

ahh maybe a pineapple sponge.

 

I was thinking a pineapple sponge or a turnicate

 

I have these ALL OVER the place in my tank. I leave them because they don't seem to be doing any harm. When my GSP goes to sleep for the night I can see about 10 of them tucked in there. They don't seem to like the light. I have a bunch in my overflows too. Kind of cool. I was told by my LFS that they were turnicates (sp.) and they were good for removing small food particles.

 

Okay, well, that's not quite as cool as I'd hoped ... but I guess I can always use more filter feeders.