There are more than 80 known types of whales, or Cetacea, which are classified into two major groups: toothed whales and baleen whales. Although they are all known as whales, they have great physical and dietary differences between them as discussed below.
Baleen Whales
Baleen whales are normally larger compared to toothed whales. The blue whale is the biggest animal on earth and it belongs to the baleen whale suborder. Blue whales can grow up to 90 feet. The smallest baleen whale is the pygmy right whale which can grow up to 21 feet. They have a filtering system composed of thousands of baleen plates. They have smaller dorsal fins (some do not even have dorsal fins) compared to toothed whales. They tend to be solitary animals, moving alone or in small groups, though they seldom get together in groups to eat or to travel. Male baleen whales are usually smaller than females.
Some Examples of Baleen Whales
- Right Whale
- Grey Whale
- Pygmy Right Whales
- Blue Whale
- Humpback Whale
- Fin Whale
Sometimes baleen whales are referred to as mustached whales. Mainly, baleen is made up of keratin, a substance that is present in our hair and fingernails. They feed on small water animals, such as plankton, fish, copepods, amphipods and krill. They use baleen to sift food out of the water. A number of them get their food through swimming with their jaws wide open. Some open their mouths and drink plenty of water. They are differentiated by two blowholes. The blowholes may be closed by sturdy, muscular flaps that open just when the whale inhales.
Toothed Whales
There are approximately 65 different types of toothed whales. They are usually smaller compared to baleen whales, though there are some that are fairly large like the Baird’s beaked whale and the sperm whale. The sperm whale is longer than 13 metres and can grow up to 18 meters. All types of dolphins and porpoises belong to toothed whales. They are active predators and hunters. They find, hunt and then catch prey using their teeth. When they catch their prey, they swallow it whole. They feed on various species, such as fish, squid, sea lions, seals crabs, starfish and even other whales. Moreover, they have a stronger social structure compared to baleen whales, frequently gathering in pods.
Examples of Toothed Whales
- Beluga Whale
- Sperm Whale
- Bottlenose Dolphin
- Chinese River Dolphin
- Amazon River Dolphin
- Pilot Whales
- Killer whales
Contrary to baleen whales, females toothed whales are usually smaller than males. They are differentiated by one blowhole. Toothed whales swim faster as compared to baleen whales. Toothed whale reproduction is fairly fast compared to baleen whale.
Toothed whales get their food by means of echolocation while Baleen whales lack the echolocation capability. Echolocation functions like a navigation system which may detect objects, like squid, in the water. Through its nasal passage, the whale sends signals, known as “ultrasounds”. These signals rebound or “echo” off prey, then come back to the whale, providing a lucid “sound-picture” of the prey’s size, form and location.