What is the largest living mammal?

The largest living mammal is the blue whale, Balaenoptera musculus. It is also the largest animal known to have existed, surpassing every known terrestrial mammal in both length and overall mass.

Blue whales are baleen whales, meaning they filter food from seawater instead of using teeth. They feed mainly on tiny crustaceans called krill, which they strain through baleen plates while taking in enormous mouthfuls of water. Despite their size, their diet consists of some of the smallest marine animals.

A blue whale can exceed 30 meters in length, although size varies by individual and population. Females are generally larger than males, and Antarctic blue whales tend to be especially massive. Their heart alone can weigh hundreds of kilograms, while their powerful tail propels them through the ocean.

The African bush elephant is the largest living land mammal, but it is far smaller than a blue whale. Another common mix-up is calling the whale merely the largest mammal; it is more precise to say it is the largest known animal overall, living or extinct, based on current evidence.