i have a cluster of polyps that were doing great until a few weeks ago. Now they don't open all the way and look sort of shriveled. I was walking by the tank today and happened to catch out of the corner of my exe what looked like a thin white worm thing pop out of the middle of a closed up polyp. it poped out poped back in and did that 2-3 times and i never seen it again. Is this a parasite? What is going on? Anyone know?