The sperm whale or cachalot is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus Physeter and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.
Image: Mother and baby sperm whale
Image: Sperm whale distribution (Pacific equirectangular)
Unusual among cetaceans, the sperm whale's blowhole is highly skewed to the left side of the head.
A sperm whale skeleton
The toothed whales are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. 73 species of toothed whales are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya).
A whale as depicted by Conrad Gessner, 1587, in his Historiae animalium
Fossil of Squalodon
Pacific white-sided dolphins porpoising
Spectrogram of dolphin vocalizations. Whistles, whines, and clicks are visible as upside down V's, horizontal striations, and vertical lines, respectively.
