Bristleworms are blamed for everything negative that occurs in reef tanks, but they are actually very good clean up detrivores. Count on them to find excess food missed by your fish, and expect to see many of them at night with a flashlight. They are often found on decaying matter, and thus are blamed for the death of the [insert creature here] rather than praised for keeping the tank clean. Reef-safe! Here is an extra image with a few larger ones.