My reef tank seems to be full of these little centipede looking creatures? They're white and when I move a rock I see them crawling around in the sand.... what are they? are they harmful? should I be worried about them? Any suggestions???
They look like tiny arms of a brittle star almost.... they could be gray or light brown.. one looked kind of cloudy white to me....
So I don't have to worry about them at all? They just appeared there....