Anyone recognize this black worm??? Also looking for info on catching a bobbit worm.

I am a new salt water tank owner, and we have live rock and live sand. Recently we had a goby get eaten, and started looking for the culprit. We found this black worm (found this unknown video of it on the net). I do not think it is what killed the goby, because last night we found the bobbit worm that lives right behind this little guy.

This worm seems to com out in the day and pick up dead matter. We believe that bobbit is what killed the goby. We need to catch the bobbit worm and get it out, but we are wondering if this other critter is worth saving.

Any information would be very appreciated.

http://www.bing.com/videos/watch/vid...202&FORM=VIRE1

PS how often do Bobbit worms show up in tanks???

Thank you very much!

Karyn