i was looking at my tank tonight and i saw my zoanthids move. i started looking a little closer and saw them split in half and what appears to be a mouth of a clam. i tried to wggle it and it wont budge. any ideas on what it is? i cant get a good picture of it because my camera sucks. i have 130w pc,s. the zoanthid colony was at the bottom of the tank. should i mave it up closer to the light? is there anyway to get it off the rock? it is covered in zoos so i cant see anything but the mouth when it opens. it is probably 2" long.