Help id this thing

[cashout]

I bought a huge Xenia coral on a big live rock and i found these clearish white
stringy looking things that pop out of a tube in the rock please tell me if this worm or whatever it is is reef safe thank you



here is a pic

http://s793.photobucket.com/user/il...-0b4fd34789eb_zps3bdeb6f8.jpg.html?sort=3&o=1