To anyone who has ever seen one, the sperm whale (Physeter macrocephalus) is among the more bizarre-looking animals on our planet. With its wrinkled skin, giant head, and large teeth arrayed in an oddly underslung jaw, it looks less like a creation of Planet Earth than something put into the world’s oceans as a prank by extraterrestrials. Yet this remarkable animal has probably been around for longer than any other living cetacean–perhaps as long as 25 million years–and it is superbly adapted to the pelagic ocean environment in which it expends its long life span. Sperm whales may well be the deepestdiving of all mammals: they can hold their breath for more than 2 hours in extreme cases, and there is good evidence that they can dive to depths of around 10,000 feet. They are a highly socially evolved species, with strong familial bonds evident in groups that travel, forage, and foster their young together. They are found in all the world’s oceans and travel thousands of miles on their wanderings.

National Marine Fisheries Service (NMFS)

North Pacific