I've had this reef tank for a good 6 months now, everything has been doing great. My diamond goby disappeared a couple weeks ago and now there are these little clusters of orange worms appearing all over the sand. I know they didnt kill him, but he was keeping the sand stirred. They seem to be partially buried with the other parts sticking out and just laying on the sand, gathering food. Any idea what they are or how to get rid of them?