Facts About Mysticetes - the Baleen Whales

The term mysticete refers to large whales that feed using a filtering mechanism made up of baleen plates. These whales are called mysticetes or baleen whales, and they are in the taxonomic group Mysticeti. This is one out of two major groups of whales, the other of which are the odontocetes or toothed whales.

Introduction to Mysticetes

Mysticetes are carnivores, but rather than feeding with teeth, they use a straining system to eat great quantities of small fish, crustaceans or plankton in one gulp. This is made possible by their baleen plates - fringed plates made of keratin that hang down from the whale's palate in the upper jaw and are supported by its gums.  

About Baleen

Baleen plates resemble vertical blinds on the outside, but on the inside, they have a fringed edge, which is made up of thin, hair-like tubules. The hair-like tubules extend down on the inside of the whale's mouth and are supported on their outside by a smooth, fingernail-like cortex.

What is the purpose of this baleen? There are hundreds of baleen plates, and the fringe inside each overlaps to create a strainer that allows the whale to filter its food from the ocean water. To gather its food, the whale will gulp or skim the water, and pass the water in between the baleen plates, trapping the prey inside. By feeding this way, a mysticete can gather large quantities of prey but avoid swallowing much salt water. 

Characteristics of Mysticetes

The baleen is the characteristic that most defines this group of whales. But there are other things that set them apart from other whales. Mysticetes are generally large animals, and this group contains the largest species in the world - the blue whale.

All mysticetes have:

• Baleen plates, which they use for feeding
• Two blowholes
• Symmetrical skull
• Lower jawbones that are solid and do not join in the middle

In addition, female mysticetes are larger than males.

Mysticetes vs. Odontocetes

Mysticetes can be distinguished in the whale world from odontocetes. These whales have teeth, one blowhole, a skull that is asymmetrical and a melon, which is used in echolocation.  Odontocetes also have more variability in size. Rather than all being large or small, they range in size from under three feet to over 50 feet. 

Mysticete Species

There are 14 currently recognized species of mysticetes, according to the Society for Marine Mammalogy.

• Blue Whale
• Fin Whale
• Sei Whale
• Bryde's Whale
• Humpback Whale
• Omura's Whale
• Common Minke Whale
• Antarctic Minke Whale
• Bowhead Whale
• North Atlantic Right Whale
• Southern Right Whale
• North Pacific Right Whale
• Pygmy Right Whale
• Gray Whale

Pronunciation: miss-tuh-seat

_{References and Further Information}

• _{Bannister, J.L. "Baleen Whales." In Perrin, W.F., Wursig, B. and J.G.M. Thewissen. Encyclopedia of Marine Mammals. Academic Press. p. 62-73.}
• _{Rice, D.W. 2002. "Baleen." In Perrin, W.F., Wursig, B. and J.G.M. Thewissen. Encyclopedia of Marine Mammals. Academic Press. p.61-62.}