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What is a cetacean?

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

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.

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Indo-Pacific bottlenose dolphin © Mike Bossley/WDC


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Humpback whale


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