Heaviest brain

The largest brain of any animal belongs to the sperm whale (Physeter macrocephalus ) and weighs approximately 9 kg (19 lb 13 oz), which is six times heavier than a human brain. Nevertheless, it only equals 0.02 per cent of the whale’s total body weight. NB: The old Latin name for the sperm whale was Physeter catodon; replaced in more recent years by P. macrocephalus.

Sperm whales are found in all waters except the polar regions. They get their name from the waxy spermaceti oil which is produced by the spermaceti organ on their heads.

In comparision the weight of a bull African elephant's brain can reach 5.4 kg (11 lb 14 oz) and a human brain is, on average 1.4 kg (3 lb).