The largest animal that has ever existed

The blue whale is the largest animal that has ever existed on Earth: bigger than any known dinosaur. It can measure 30 metres and weigh around 150 tonnes.

The figures are hard to imagine: its heart weighs close to 180 kilos, and its tongue alone weighs roughly the same as an elephant.

And it feeds, above all, on tiny crustaceans called krill. The largest giant on the planet lives off the smallest things.