The fins of the ray create a disk shape that can be round, triangular, or diamond-shaped. Rays use their pectoral fins to 'fly' through the water. Though a bony fish takes in water with its mouth, rays do not because they live at the bottom of the ocean. If they took in water through their mouths, they would probably just get a mouthful of sand. Because of this, they have breathing holes on top of their bodies called "spiracles". Rays use spiracles to take in water that is then sent over the gills.