Manta rays (Manta birostris, hāhālua in Hawaiian) are large fish, weighing up to 3,000 lbs. Their wingspan can exceed 20 feet, and the largest manta recorded was 23 ft. They have cartilaginous skeletons and are related to sharks. One of the defining features of these fish are their pair of "cephalic flaps" which act to funnel water into the mouth. When curled up, these flaps resemble horns projecting from the head. Mantas are harmless to humans, but can be quite intimidating when seen up close due to their immense size. They prey upon tiny plankton and swoop in great looping circles with their gaping mouths open wide. Similar to humpback whale fluke patterns, mantas can be identified by the pattern of blotches and dark spots on their undersides. At one time there were thought to be several species of manta but recent DNA research by Tim Clark at the University of Hawaiʻi has shown they are all the same species.