The Similarities Between the Baleen & Toothed Whales

Whales Are Mammals

• Whales are mammals and share the characteristics common to all mammals. All whales are warm blooded. They all breathe air with lungs and cannot derive oxygen from water. All nurse their young with secreted milk, and all have some hair at some point in their development. These are characteristics shared by all mammals.

Entirely Aquatic

• While there are many mammals, including seals, otters, walruses and polar bears, that spend enough time in the water to be considered marine mammals, whales never traverse land . Their entire lives are spent in the water. Only the order Sirenia, the dugongs and sea cows, share this trait with the cetaceans.

Carnivores

• The difference between the toothed and baleen whales illustrates that the two main types of whales have very different diets, but all whales are carnivores. They all eat other animals to survive. The toothed whales eat relatively large prey, such as fish, and use their teeth to tear food into more easily swallowed chunks. Baleen whales filter seawater for very small animals, such as krill, a microscopic crustacean. This is one distinction between the cetaceans and the sirenians, which are the only completely herbivorous marine mammal.

Tails

• Whales evolved from animals that lived on land. Their front legs have evolved into flippers, while their rear legs have disappeared over time, leaving only vestigial traces in modern cetaceans. Their most notable adaptation to the challenge of aqueous locomotion is their large and powerful tail. The tail flukes on baleen and toothed whales alike are oriented horizontally, and they propel themselves by moving the tail up and down. This is in contrast to fish, which have vertically oriented tail fins which they move back and forth.