The term 'moon fish' is a common name for the OPAH, a large, colorful, deep-sea fish found in tropical and temperate waters around the world. It is also known as the king of the herrings, and is the only member of its family. The scientific name for the OPAH is Lampris guttatus. It has an oval-shaped body with a bright red color on its back and sides, and a silvery-white underside. Its fins are long and pointed, and its tail is deeply forked. The OPAH is an important food source for many cultures, and is often served as sushi or sashimi.