The melon is an oval shaped oily, fatty lump of tissue found at the centre of the forehead of most dolphins and toothed whales, located between the blowhole and the end of the head. The function of the melon is not completely understood, but scientists believe it provides a means of focusing sounds used in echolocation. Some scientists also believe the melon may function in deep diving and buoyancy. Melon size tends to increase in toothed whales that dive deep. Some species' melons are more developed and specialized than others. The Sperm Whale has specialized sufficiently that the oil within the organ is chemically distinct from that found in other toothed whales. In fact, the differences in size and composition are so great that the organ has its own name: the spermaceti organ, which contains the waxy substance used for candlemaking when the whales were originally hunted. The melon of the Beluga is also unique. Part of its adaptation to its icy environment is to do more with its melon (though scientists aren't exactly sure what) by changing its shape at will.
