What Are the Big Differences Between Dolphins & Whales?

Size and Movement

• The baleen whale is usually larger than a toothed whale. The blue whale, which is baleen, is the largest mammal in the ocean. It can grow up to 89 feet in length. A female baleen is usually larger than the male. In comparison, the killer whale is the largest dolphin and grows up to 32 feet long. Unlike the baleen, the female toothed whale is smaller than the male. As a result of its size, a baleen swims at a slower pace and is not as agile as small toothed whales, like the bottlenose dolphin. Baleen whales have been the target of whaling because they are slower and easier to catch.

Teeth

• A big difference between the two groups is teeth. Toothed whales are grouped together because they have teeth. The toothed whale doesn't use its teeth to chew food. Instead, it uses them to tear big prey into pieces and swallow those pieces whole. They use their teeth to defend themselves from an attack from predators. Also, a male toothed whale will fight another male for the right to mate with a female during the mating season. Baleen whales do not have any teeth but instead a row of plates in its jaw.

Diet

• Because of the difference in teeth, there is a big difference between the diet of baleen and toothed whales. Without teeth, the baleen whale uses a filtering system in its mouth to eat food low on the food chain. Its diet is mainly zooplankton, small crustaceans, krill and other small sea life. It will open its mouth and take in food and water. The water is then filtered out of the body, leaving food in the mouth ready to be swallowed. The toothed whale eats much larger food, like seals, sea lions, sharks and other whales. It is a predatory eater.

Social Behavior

• Baleen whales are solitary animals. The only time a baleen will be in a group is during migration and mating. A calf will swim close to its mother as she guides and protects him. In contrast, toothed whales are sociable and live in groups. For example, a group of bottlenose dolphins will hunt and live together. Groups are often multigenerational; a female dolphin may return to its mother when she wants to raise her own calves.