I recently acquired 4 sps frags. When I recived them, the first thing I did is cutting off the plug and dipped it in redsea coral dip then observe (nothing falling off).I then placed it on a frag rack and start one week observation. After one week, I did not notice anything wrong with those frags except one frag has tiny PE. I mounted all them on my rockwork. Last night I decided to pull that piece out and observe it closely after 20 mins this sucker showed up. I did a 4x interceptor dose in the main tank and pull out all three frags guess what they all have this on the base. The interceptor did nothing to them. It looks kind different than other black bug. It has foot on them not the slug or flatworm looking one. So What's now guy?