Whale of fat, and the skull of any such creature containing a melon will have a large depression. The melon size varies between species, the bigger the more dependent they are of it. A beaked whale for example has a small bulge sitting on top of its skull, whereas a sperm whale's head is filled up mainly with the melon. The whale eye is relatively small for its size, yet they do retain a good degree of eyesight. As well as this, the eyes of a whale are placed on the sides of its head, so their vision consists of two
Whale lungs can hold about 5,000 litres of air. Spout shapes differ among species, which facilitates identification. The heart of a whale weighs about 180–200 kg. It is 640 times bigger than a human heart. The heart of the blue whale is the largest of any animal, and the walls of the arteries in the heart have been described as being "as thick as an iPhone 6 Plus is long". All whales have a thick layer of blubber. In species that live near the poles, the blubber can be as thick as 11 inches. This blubber can help with buoyancy (which