Help identifying hitchhiker (sponge?)

[Reefer Addict]

Hi All,
Well, the ol' tank finally cycled, and my first purchase was a Colony Star Polyp. As I was placing it in my tank, this little guy popped out of the bottom of the colony mass. At first I kinda thought it was a piece of the polyp colony, but it looks a lot different, almost like a sponge to me... but then again, what do I know?
It's kinda leathery and soft. When I touch the tip that's opened up it contracts and closes. It has 4-5 other 'siphons' (for lack of a better word) that emanate out from the base also, a couple of which you can see in the picture.
Anybody have any idea what this is?
TIA
David

[Reefer Addict]

Here's more of an overhead pic of the main tube.

[foobuddha]

When my zooanthids bud, that's what they look like before the sweepers become defined. But then again - I know next to nothing ;^}

[gumhead]

yup looks like some kind of sand polyps or zoos

[wildthings44]

Looks just like my smaller moon polyps!!!
Just wait until it opens and if it's center is green, then I'd hazard to guess that it.
What ever it is I would say at least a polyp of some kind...

[Reefer Addict]

Thanks for the identifications... I mainly wanted to make sure that it wasn't a 'pest' specimen.
I'll keep an eye on it and post pictures ever so often...
The reason I thought it was a sponge was that it's sorta hollowed out on the inside, but not completely... only about the first third of it.
I was surprised to find a hitchhiker on an LFS purchase though... I thought they only came with live rock.
Thanks again.

[wildthings44]

heh you should see my "xenia" rock (I think it was anthelia...) All the orriginal coral died and then I had pretty green button polyps and halimeda... and some shrooms... any way...

[Reefer Addict]

Well, I did a bit of rearranging in the tank and moved the 'polyp' to a different spot... where I could get a better picture of it (the glass added a lot of distortion to the first picture).
It's an orangish-red color and when only the actinics are on, the lip toward the inside glows a bit of green (like mentioned above about moon polyps). Anyway, here it is (and it seems to be doing quite well so far):
Thanks again.

[Reefer Addict]

Well, I think I figured out what it is... quite possibly a brown button polyp.
I found this picture of them over at Premium Aquatics, and what I have pretty much looks like an immature version of what's in this picture.