Help ID Unknown worm on Live Rock

[maddv]

Hi I have a 72G SW running for 6 months. Introduced 40lb of cured live rock from somebody who broke down their aquarium 4 months back. Since then they have been in my tank. I just discovered several small black worm type creatures dwelling in my rock just peaking out once in a while they dont come out. Dont know if i have a good one or a bad one. Have several of them all over the rock. Attached is a picture. Can somebody ID this and advice what I need to do.

Thanks

 

[Reefscape]

Is it black and white bands on it? or brown? A closer pic would be great..

 

[Charlesr1958]

From the photo, it looks more like the arm of a brittle starfish, to me.

Chuck

 

[arpy]

Might be a Peanut Worm...? Looks like the ones I have but with much darker lines. They just hide in holes in the rock and stick part of their body out to feed. I have only seen one completely out of a rock... and only long enough to move to a new hole.