Please ID worm. Thanks!

[Jcampbell]

I found this worm swimming in my marine tank. It appears to have a white head and pink body. When it swims it wiggles it's body. Very fast moving worm! It's about an inch long, likes to swim in the current, and comes out at night. Picture attached. What is it? Is it safe to have in a marine tank?

 

[cloak]

Polychaete epitoke most likely. (harmless in most cases)

 

[Jcampbell]

That's it. I just watched an online video of the worm swimming. Harmless in most cases. What should I be concerned about? Thanks!