hitchhiker worm

Hello good people of R2R, I have what I think is a Eunice worm in my tank but would love to hear that I am wrong. It decided to come out with the lights on today and I was able to get a decent look at it, and even snap some terrible photos- it is VERY sensitive to movement so unfortunately these...

Hi! I noticed a nasty lil worm thing moving, inching its way out of a hole in the rock. Obviously I was curious to see what the heck it was so I turned the tank light on and it shrunk back in the hole. I'm new to saltwater tank keeping so I just want to make sure this isn't a harmful parasite of...

I see these stringy things coming out of the sand all the time. I believe the worm stays under the sand and puts the strings out. I saw it on the glass and tried to take some pictures. Let me know if you can identify this. Thanks