I've seen this guy around a few times, I figured he was just another bristleworm, and I know that fireworms are just a subspecies of bristleworm, but this one has a very specific habit that I do not appreciate... HE ATE MY ZOANTHIDS! I caught him mid polyp on some gorgeous green zoas. He's in my sump now, where the only thing available is detritus and the only way out is to become fish food.
