Help please. I just got a huge rock with corals on it from a local reefer. It was too big and funky shaped to QT it. I had it in a bin and used coral dip for 5-6 minuites, then changed out the water and sprayed it down and left it in clean water at 1.040 salinity for another 15 minutes. I didn't see any worms in the water either time. Tonight though, a bunch of these worms started swimming up to the surface from the rock. They swim like a helicopter propeller. I've looked through the forums but haven't positively I'D these guys. I read there's a free swimming stage for bristle worms, but I have bristle worms and have never had these before... Are they dangerous? Is there anything that eats them?