Saw this while feeding my invert heavy tank. It is most definitely NOT a bristle worm… I have several of those in my tank and know them fairly well. This guy has a face that reminds me of a coolie loach… i think it’s been in my tank for at least 8 months. It seems to be more of a rock dweller than a klinger. I have two fire fish that have been sleeping in that same rock for the same duration of time, they have never been bothered. Nether has the antipsta filefish who favors hanging out on that side of the tank. I have lost a few rainsford gobies, which I thought were hunted by the saron shrimp in the tank…. Now I am curious.