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Cetaceans

Cetaceans are aquatic mammals, including whales, dolphins and porpoises. Their bodies are adapted for swimming, but they breathe air with lungs and feed their young with milk. Although their shape can resemble that of fish, they belong to a different animal group.

Two main groups of cetaceans

  • Baleen whales, such as blue whales and humpback whales, filter food using plates made of keratin.
  • Toothed cetaceans include dolphins, orcas, sperm whales and narwhals. Diet and hunting methods differ between species.

The orca, also called the killer whale, belongs to the dolphin family. Common names do not always show exact zoological relationships.

How are cetaceans different from marine mammals?

Marine mammals are a broader group. They also include seals, walruses, sea lions and manatees, which are not cetaceans. Most cetaceans live in seas and oceans, but some dolphins are adapted to rivers.

Ocean-dwelling cetaceans belong to the diversity of marine mammals and other marine animals.