something in my liverock?

[r6danger]

i have something growing in a hole in my live rock...looks like a flower...it's white and when fish swim by it goes back in the hole...what is it?

 

[pezlok]

It is most likly a feather duster. It is a filter feeder.

 

[wolffam]

It's a feather duster. I have several that seemed to have shown up after a while. Just spotted another on last night.