Parrotfish
Parrotfish Scaridae are a natural wonder for many reasons. First off, their colors are as vibrant as the tropical waters they inhabit, and they can change colors many times as they develop through life. Some male parrotfish actually maintain harems of females, and most interestingly, if the dominant male dies, one of the females in the harem will change gender and color to become the new dominant male. Parrotfish have the ability to change genders multiple times through their life. Parrotfish use their grinding teeth to pulverize corals, so that they can eat the algae living inside the coral polyps. Much of the white sand found in tropical coasts is actually made by parrotfish breaking down corals. There are over 80 species of Parrotfish found throughout the world's tropical and sub-tropical oceans. Caption credits: The TerraMar Project