Need an ID on this hitchhiker..

[rottielover]

I tried in vain to enhance this pic...

This ...thing... is about 5 mm long and sticking off some live rock. On the "top" of it there are "hairs" in a sphere.

What is it, and do I need to get rid of it?

Thanks

Forgot to mention, right after the pic was taken the "hairs" closed up and disapeared for about 20 min, at which point they re-appeard. So the creature is light sensitive, in that it closed after the flash.

[rottielover]

oh ya, it hasn't moved for over a week now, so I think it must be anchored into the rock somehow.

[jdbassin]

hard to tell by the pic but it sounds like one of the many small fan worms to me, harmless