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What is a cetacean?

Cetacean is the collective noun used to describe all 90 species of whales, dolphins and porpoises.

The word cetacean has its origins in Latin (Cetus) referring to a large sea creature and Greek (Ketos) meaning whale or sea monster.

Having evolved around 50 million years ago, today they are separated into two distinct types - Mysticeti (baleen whales) and Odonotoceti (toothed whales).

The baleen whales are made up of most of the larger whales, such as the blue whale and humpback whale. One notable exception is the sperm whale which is a toothed whale.

The other toothed whales include all dolphins, porpoises and beaked whales. Beluga whales and narwhals also belong to this grouping.

Amazon River dolphin (Boto)

What are the differences between whales, dolphins and porpoises?

From the enormous blue whale to the tiny vaquita, they share many characteristics but also have some distinctive features which set them apart.

Amazing facts about whales and dolphins

Dive deeper into the world of whales and dolphins and learn more about their lives.

A humpback whale pokes its head partway out of the water, a behavior called spyhopping

Facts about whales

Amazing facts about whales, the largest mammals to live on Earth.

two dolphins diving down out of the water

Facts about dolphins

From the orca to the tiny vaquita, learn more about these creatures.

Northern Resident orca, Fife, swimming at the surface

Record breakers

Whales and dolphins hold some incredible records.

Breaching North Atlantic right whale

Brain power

Just how intelligent are whales and dolphins?

Please help us save dolphins

By adopting a whale or dolphin, by making a donation, or by fundraising for WDC, you can help us provide a safe future for these amazing creatures.

Bottlenose dolphin at surface

Adopt

Adopt a dolphin and help us protect these amazing creatures.

Humpback whale

Donate

Your gifts help us take action for whales and dolphins.

Orca spyhop

Fundraise

Run, bake, walk, cycle… what could you do for whales and dolphins?