Looking at the printed reef one right now. Surprisingly I've never found a single one in almost two years in my display tank. I had a pom pom crab, haven't seen it in a little while so it could have died of old age, but supposedly they eat bristle worms.We have common bristleworms. I was worried they were a bad one, or a fireworm at first. Then after extensive googling haha, I was able to identify them as commons. Was definitely relived, since I read some other can eat corals also. They make some bristle/fireworm traps that are 3D printed. I think they say they work pretty well.
I've found a few while dipping and kept them out as far as I know. No idea how this fireworm got into the frag tank. I had a couple mushroom corals get eaten. They were super irritated for no reason, had their messenterial filaments out and disappearing over the course of a couple days. Guess it was a fireworm. My frag tank is super simple, mostly all softies and parameters right in line with the display, 2 and a half gallon water change weekly keeps everything in place.