Brittle Stars (Ophiothrix spiculata) ~ These feathery creatures are related to sea stars and are very fragile as their arms can break off if handled.  This is a defense mechanism and those arms regenerate quickly.   An entire new organism can regenerate if the broken arm is attached to a seizable portion of the disk.  They are often found in groups under flat rocks.  They can move rapidly with their podia (tube feet). That being said, they are gentle, very delicate creatures that do not harm humans. They are nocturnal (feed and move about primarily at night); they stretch out to catch food particles, passing the bits down to the central mouth.