So tonight when I went to check on my clownfish (had just done so an hour before and they were fine) one of them went mysteriously missing. I looked everywhere, in the overflow in the return in the skimmer area, in the tank itself nowhere to be found. Has anyone ever had this before? Also, as I was looking in my tank at night I noticed a large bristleworm, probably atleast 1" in length... I hear mixed things about them being harmful to the tank, opinions?