Centipede looking thing

[cre]

I was recently moving some live rock in my tank and I noticed a Centipede looking thing that came off the rock! Does anyone know what this is? Also I have been hearing about Bristle worms. What are they and what do they look like..
Thanks

 

[chris l]

They are redish pink in the body with little white looking spines on the sides.

 

[shootonsite]

Bristleworms that are an inch or two are fine. They're beneficial to the existence of a live sand bed. It's the ones that are 5" and up that you really have to worry about. They will attack shrimp and bivalves.