Radial symmetry is symmetry about a central axis. Some radially symmetric animals include jellyfish and sea stars (pictured). Sea stars exhibit a special kind of radial symmetry known as pentamerism. This means that each of the five symmetrical parts of the organism exists 72 degrees from each other. In sea stars, the central axis of symmetry intersects the mouth on the oral surface and the center of the aboral end on the opposite side. Sea stars (along with sea urchins and sand dollars) only have radial symmetry as adults (when they are larvae, they have bilateral symmetry).