Yes, those are the clear type flatworms. I would get a wrasse to take care of them or use Flatworm Exit since these don't tend to be any direct thread to corals as I know of. But having flatworm in the tank is never a comfortable feeling. Keep in mind that if you do have a lot of them and decided to nuke them by using Flatworm Exit, the amount of toxin release when they die may aversely affect your fish.