Whale Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales). Whales are creatures of the open ocean; they feed, mate, give birth, suckle and raise their young at sea. So extreme is their adaptation to life underwater that they are unable to survive on land. Whales range in size from the and dwarf sperm whale to the and blue whale, which is the largest creature that has ever lived. The sperm whale is the largest toothed predator on earth. Several species exhibit sexual dimorphism, in that the females are larger
Right whale single female, suggesting that sperm competition is an important factor in mating behavior. Although the blue whale is the largest animal on the planet, the testes of the right whale are actually ten times larger than those of the blue whale – with each weighing up to , they are by far the largest of any animal on Earth. Gestation tends to last a year, and calves are born at in weight and in length. Weaning occurs after eight months. Right whales were a preferred target for whalers because of their docile nature, their slow surface-skimming feeding behaviors, their tendency