wierd worm thing on zoa frag

[hollywood11892]

so i just glanced over at my zoas and i noticed a worm thing like coming out of a tube it look like and grabing the zoa and then going back in iv never seen this before and i cant get a pic any ideas

 

[redsea]

Maybe a bristle worm????

 

[hollywood11892]

are they bad should i be worried