The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
These have just appeared on my rocks in the last month or 2. Seem to only be on this rock and starting on another rock touching this one. They do seem to be increasing in numbers though. Is this some type of worm?
IMO they are mini feather dusters. Try spotting them after lights out with a flash light. In fact take the time to check the rest of your tank for other critters, it's amazing what will come with your live rock.