The right whales are marine mammals belonging to the family Balaenidae. Right whales are baleen whales belonging to the family Balaenidae. Three right whale species are recognized in the genus Eubalaena, while the Bowhead Whale-also a right whale-is placed in its own genus, Balaena. Right whales can grow up to 18 m (60 feet) long and weigh up to 100 tonnes. Their rotund bodies are mostly black, with distinctive white callosities (skin abrasions) on their heads. They are called "right whales" because whalers thought the whales were the "right" ones to hunt, as they float when killed and often swim within sight of the shore. Populations were vastly reduced by intensive harvesting during the active years of the whaling industry. Today, instead of hunting them, people often watch these acrobatic whales for pleasure. The four right whale species live in distinct locations: around 300 Atlantic Northern Right Whales live in the North Atlantic; approximately 200 Pacific Northern Right Whales live in the North Pacific; about 7,500 Southern Right Whales are spread throughout the southern part of the Southern Hemisphere; and 8,000–9,200 Bowhead Whales are distributed entirely in the Arctic Ocean.