What's this in my liverock?

I have a peice of rock that has a bunch of nooks and crannys and i keep seeing little tenticals coming out of very small holes in the rock.There not much bigger than a human hair,i can't get a seeable pic,but the tenticals feel around like there looking for food,some of them look like a birds feather in it's shape,and others look smooth like a very tiny thin worm,but both types i see,can and do,retract quickly if something swims by.Any ideas to what they might be?

 

initial guess is a mini brittle star. harmless.

 

Without picture it is hard to tell but could be feather duster, some type of polyp, aiptasia, if it was not for the retraction part I would guess brittle star (I have a couple that look similiar to your description).

 

Micro brittle legs, spaghetti worm, hair worm, medusa worm. Could be any of those and if so nothing to worry about.

 

aiptasia don't have feeler tenticals do they?I know exactly what aiptasia look like,and i have quite a few very,very small feather dusters,i'm sure it's neither of those.I wish i could get i pic,i've tried but when i try to focus in they are blurred just a little,but enough that you can't see 'em

 

A couple of those worms sound scary,i wonder if the feathery looking one are baby brittle,if so,will they grow into a full sized star,or do they stay small,hence micro

 

google the suggestions everyone has made and see if you find a match.
Xtalreef

 

I would say spaghetti worm. I have had a few in various tanks and they have never done any harm to anything. Not that I have noticed atleast.

 

Great sugestion,i'll do that and thanks for the link.

 

The micro brittles get as big as a quarter IME. LOL don't let the names worry you. The medusa worms look nasty in pics cuz you see the whole thing. In the tank all you see is a bunch of stretchy "hairs" sweep over the rocks. That's the worms tentacles dragging food and material to build tubes back to the body.