Weird bubble on Green Star Polyp rock

[flightboy123]

So I got a rock with green star polyps in manhattan, NYC at saltwater store i prefer.

Acclimating great to my tank! Polyps looking great and growing already!

something i cant identify.... on 1 edge of the rock by a polyp is a glass tube slightly frosted white, what can only look like the shape of the end of a Q-tip to describe it, and more thin and if it gets startled it retracts, and then will project out a bit. It is not more than a half a inch, very small. Also the tip has a tiny opening on it.

What on earth is this hitchhiker?? A tunicate/sea squirt is my best guess as it does have two siphons or small hose like shapes that extend beyond the little sack, with a hole on top of the extensions. If it is that, what do I do for it?

 

[Jaybird]

Without a picture I would have to take a wild guess. Based on your description is is likely a q-tip sponge.

 

[mr_X]

it's probably a tunicate. sounds like it from your description. there is nothing special to do for it. just keep good water parameters.
if it was a Q-tip sponge, it wouldn't be able to retract as a defense.
tunicates are probably the most interesting creatures in the ocean.
here...some interesting reading-
http://academics.smcvt.edu/dfacey/AquaticBiology/Coastal Pages/Tunicates.html