Mellita quinquiesperforata

Mellita quinquiesperforata (Leske, 1778) is a tropical species of sand dollar, a flat, round marine animal related to sea urchins, starfish, and other echinoderms. They have been found to possess significantly more food in the gut at night than in the day. This species can be found along the eastern coast of the United States and the coast of Brazil. Inverted sand dollars are able to recognize flow direction and respond by modifying their orientation to maximize lift and drag for righting their position.