Bigger than any dinosaur
The blue whale is the largest animal known to have lived: as long as three buses and as heavy as 30 elephants.
Open ocean
Blue whale
Balaenoptera musculus
A vast, long, blue-grey whale, mottled with paler patches, with a tiny fin far down its back.
- Size
- Up to 30m long: the biggest animal ever
- Look for it
- All year round
- Where
- Every ocean except the high Arctic
Glides after you with slow beats of its tail. Move your pointer and see.
When to look
Blue whale
Good to know
Six things about the blue whale
A heart like a car
Its heart is the size of a small car, and beats only a few times a minute during a dive.
Tiny food
This giant feeds almost entirely on krill, each no longer than your finger. It eats about four tonnes a day.
A sieve for a mouth
Instead of teeth it has plates of baleen, like stiff brushes, that strain krill from a huge gulp of water.
The loudest animal
Its low calls are louder than a jet engine and can travel hundreds of miles under water.
The biggest baby
A calf is seven metres long at birth and puts on about 90 kilograms a day.
The real thing
Photos of the blue whale
Photos are from Wikimedia Commons, used under the free licences shown. They have been resized, and cropped where they appear in link previews.
How to spot one
Look for a tall, straight blow, as high as a house, then a long blue-grey back that seems to go on for ever. Boats see them off Iceland, the Azores, California and Sri Lanka.
How to help
Blue whales were hunted almost to extinction and are still endangered. Slower ships and shipping lanes moved away from feeding grounds save lives.
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