The sperm whale is the most famous of the Physeteridae family. It is also the largest of the toothed whales and may dive deeper than any other cetacean. Herman Melville made the sperm whale famous in his classic novel Moby Dick. The sperm whale received its name from an organ inside
its head - the spermaceti organ - that old-time whalers used to believe produced sperm. Instead, the spermaceti organ contains high quality oil. Sperm whales are very difficult to study because they
spend most of their time in open water, away from coastlines. Sperm whales can dive to 3000 feet (915 meters) in pursuit of giant squid, their primary prey.
Throughout history, humans hunted toothed whales for oil and food. Sperm whales are prized by commercial whalers for the large amount of oil that could be produced from their blubber and spermaceti organ and for ambergris (a waxy substance that forms around squid beaks in the whales' intestines), which was used to make perfume. Sperm whales are still classified as endangered because of the great numbers that were killed by commercial whaling through the 17th to early 20th centuries.
Male sperm whales grow to about 60 feet (18.3 meters) while female sperm whales grow to approximately 43 feet (13.1 meters) long. Male and female sperm whales have huge, squarish foreheads, small inconspicuous eyes, and a long narrow lower jaw. Sperm whales have one blowhole located at the left of the forehead.