What is the largest animal in the world?

The largest animal in the world is the blue whale.

The blue whale (Balaenoptera musculus) is the largest known animal both today and in the whole history of the Earth – larger than any known dinosaur. It is also the world’s largest mammal, since all whales are mammals.

The size of the blue whale

A blue whale can grow to more than 30 metres long and weigh more than 150 tonnes. Its heart is roughly the size of a small car, and its tongue alone can weigh as much as an elephant. Blue whales usually swim at a leisurely pace, but they can accelerate to around 50 kilometres per hour when needed. They are also among the loudest animals: their low-frequency calls carry a very long way under water.

Habitat and diet

Blue whales live in all the world’s oceans and especially favour cold, deep waters. They make long annual migrations, usually spending the summer in feeding areas near the polar regions and the winter in warmer waters, where they also breed. Blue whales are filter feeders that eat mainly krill, small shrimp-like crustaceans. In the richest feeding season a single whale can eat several tonnes of krill a day, filtering it from the water with the baleen plates in its mouth.

Endangerment and protection

The blue whale population declined sharply in the first half of the 20th century as a result of large-scale commercial whaling, and the species is still endangered. Today blue whales are protected by international agreements, including the CITES convention and the whaling moratorium of the International Whaling Commission (IWC), and populations are slowly recovering in several areas.

Sources: WWF, National Geographic, IUCN Red List