I have no idea where this goes, so ill put it here. I have these things in my tank that resemble pieces of yellow thread, but they move. If i touch them they retract and then extend when I leave them alone. They originate in one spot and go out from there like a starfish kind of. I can try to get a picture tommorow. Does anybody know what these are? One group is in my starpolyps the other in a hole in a rock.