tiny tentacles coming out of LR, what the?

[Fernster]

Hello.
Recently I bought some shrooms for my 25G. Soon after putting it in my tank I noticed groups of about 3 or 4 tiny gray tentacles poking out of several crevices in the shroom rock. To me they resemble tiny octopus tentacles, less than 1/3 of an inch in length, they don't look like bristle worms or any other type of worm I've seen. Now I've discovered these mysterious tentacles on my LR. I have never seen these before. Any ideas as to what these might be and should I be concerned?

[plyle02]

bristle star?

[Fernster]

I just looked up a picture.. that's exactly what it is, bristle stars. Should I be concerned?
thanks.

[Sk8r]

http://reefkeeping.com/issues/2005-01/rs/index.php