could you post a picture of them? i have a ton of bristle worms in my tank, they are half black half red, but have not harmed any living things, only eating a dead snail and detritus. i have xenia, mushrooms, and some small anemones. It would be great if we could figure out which are the harmless ones, and which are harmful.
also, do any fish eat these? my cinnamon clowns dont... angelfish maybe?