Largest animal ever

About the blue whale

The blue whale holds the record for the largest animal, at 165 tons (150 tonnes). Blue whales belong to the baleen whale family. Their mottled blue-gray color looks light blue underwater, which gives the species its name. They feed almost exclusively on krill and are found in all oceans except the Arctic. They typically swim at about 5 miles an hour while feeding and traveling.

How the size varies

Size varies by population. In the North Atlantic and North Pacific, blue whales can grow to about 90 feet and weigh over 100,000 pounds. Antarctic blue whales are generally larger, reaching about 110 feet and weighing more than 330,000 pounds. Female blue whales are generally larger than males.

Conservation and threats

Commercial whaling sharply reduced blue whale numbers in the early 1900s. Populations are increasing globally today. The species is listed as endangered under the Endangered Species Act and protected under the Marine Mammal Protection Act. The main current threats are vessel strikes and entanglement in fishing gear.