A few months ago a had royal damsel disappear from my tank. I never found the fish or any remnants of it. This past week my Bartletts anthia and two emerald crabs have also gone missing without a trace. My thought was that the anthia flopped out of the tank and made a midnight snack for my cat, but because I'm certain my crabs didn't flop out, I'm not convinced my fish did either. I'm starting to think I have an unwanted guest lurking in my tank preying on my livestock. I found a one inch bristle worm crawling on the side of my tank and quickly removed it about four days ago. Aside from that I haven't seen anything unusual. Has anyone had similar experiences?