Blue whale breach
Dwarfed by the vast expanse of the open ocean, the biggest animal that has ever lived on our planet: a blue whale. Thirty metres long and weighing over 200 tonnes, it's far bigger than even the biggest dinosaur. Its tongue weighs as much as an elephant, its heart is the size of a car and some of its blood vessels are so wide you could swim down them. Its tail alone is the width of a small aircraft's wings. Its streamlining, close to perfection, enables it to cruise at 20 knots - one of the fastest creatures in the sea. The ocean's largest inhabitant feeds almost exclusively on one of the smallest - krill. A single whale can consume 40 million of them in a day. Despite their enormous size, we know very little about them. Their migration routes are a mystery and we have absolutely no idea where they go to breed. They are a dramatic reminder about how much we still have to learn about the ocean and the creatures that live there.