This distinction is important because whales belong to one of two groups - the odontocetes or the mysticetes (the baleen whales). The toothed whales include all species of dolphins and porpoises, which numbers about 70 species of cetaceans.
In addition to the presence of teeth, toothed whales typically:
- Are generally smaller than baleen whales, although there are some exceptions (e.g., the sperm whale and Baird's beaked whale).
- Are active predators and use their teeth to catch their prey and swallow it whole. The prey varies depending on species, but can include fish, seals, sea lions or even other whales.
- Have a much stronger social structure than baleen whales, often gathering in pods with a stable social structure.
- Have one blowhole on top of their head, instead of two like baleen whales.