Sperm whale pod surfacing, Dominica

© Franco Banfi/Minden Picture

Sperm whale

Ahoy there, giants of the sea! These are the sperm whales off the coast of the Caribbean Island of Dominica. The planet's 92 whale species are split between baleen whales and toothed whales. Baleen whales use bristle-like mouth parts to filter krill from the water. The sperm whales pictured here, like the other 76 toothed species, use cone-shaped teeth to attack their prey. Unlike baleen whales, they hunt and navigate using echolocation, a method that uses sound to detect the things around them. Sperm whales also happen to have the largest brain of any animal on Earth! A whale's large brain-to-body mass ratio means that their intelligence is no fluke.