The prize for the animal with the largest brain goes to Sperm whale. The average weight of an adult male sperm whale’s brain is 7.8 kg compared to 1.4 kg for a human brain.
The sperm whale’s distinctive shape makes it instantly recognizable, especially its square head, which appears disproportionately large – comprising up to a third of the whale’s body length.
However, it is another element of this massive skull that historically means a sperm whale was hunted.
The sperm organ is filled with a pale, waxy fluid that was once prized by whalers. They are thought to be involved in buoyancy control and a sophisticated acoustic sensory system that enables these social whales to relate to their complex three-dimensional environment and form complex social bonds.
Main image: © Getty Images
