Sperm Whales: Physeteridae

Physical characteristics: The pygmy sperm whale is one of two small species in this family. These whales are about 11 feet long (3.4 meters) and weigh about 600 pounds (400 kilograms). They have blue-gray backs and a shape that makes them look something like a shark. Unlike the giant sperm whale, their head is only about 15 percent of their body length. They also have a much smaller spermaceti organ, and their blowhole is located on the left side of the forehead. Pygmy sperm whales have about thirty sharp, curved teeth only in the lower jaw.

Geographic range: These whales are found worldwide in temperate and tropical water.

Habitat: Pygmy sperm whales live in deep ocean and less deep water over continental shelves. They prefer moderate or warm waters and avoid the very cold waters of the Arctic.

Pygmy sperm whales are rarely seen, and little is known about their behavior. (Illustration by Bruce Worden. Reproduced by permission.)

Diet: Pygmy sperm whales feed on squid, octopus, fish, and crabs. They eat deep-dwelling species as well as species that live in the less deep waters over continental shelves.

Behavior and reproduction: Little is known about these animals. They have been seen floating without moving on the surface or swimming slowly. They are not often observed, but when they are seen, they are often in mother-calf pairs or in groups of fewer than five animals. These animals appear to give birth to a single calf every year after a pregnancy lasting eleven months. Beyond that, little is known about their mating behavior.

Pygmy sperm whales and people: These animals are rarely seen. Occasionally they are accidentally caught in fishing gear.

Conservation status: Too little is known about the population of pygmy sperm whales to give them a conservation rating. ∎