I discovered this fact while investigating human earwax (for my entry “Funny things about humans”). And as I thought about it a bit, I came up with a few questions about whales. What are some of the main features of a whale’s body? What kinds of features distinguish different whale species? What’s the smallest whale in the world? And do all whales have earwax?
There are 2 kinds of whales – baleen whales and toothed whales. Baleen whales are also known as whalebone whales, great whales, or Mysticeti. They are one of 2 suborders that make up Cetacea (that is, all whales, dolphins and porpoises). The main feature of these whales is their lack of teeth. Instead of teeth, they have baleen plates that filter food from water like a sieve. Baleen plates are composed mostly of a protein called keratin, and they are arranged in 2 parallel rows that grow out of the upper jaw. It looks like combs of thick hair. A baleen plate can be anywhere from 2 to 12 feet long, and weigh up to 90 pounds, and will grow continually throughout the lifespan of the whale, with the end continually wearing away. In contrast to baleen whales, toothed whales (also known as Odontoceti) have teeth
(though you probably had guessed that already). These teeth are mostly used for eating, though they can also be used for aggression. There is a wide variety in teeth among toothed whales. Some dolphins have over 100 teeth in the jaws, while the narwhal whale has a single tooth (which looks like a tusk protruding from the left side of the mouth). Baleen whales and toothed whales also have different kinds of blowholes. A whale’s blowhole is analogous to our nostrils, the hole in the head through which the animal breathes. In contrast to mammals, though, a whale’s blowhole does not actually connect to the esophagus (the tube that food goes through from the mouth to the stomach). It only connects to the trachea (the windpipe). Because of this, a whale cannot breathe through its mouth. It must breathe through its blowhole on the top of its head. Baleen whales actually have 2 blowholes positioned in a V-shape, while toothed whales have a single blowhole.
Baleen whales tend to be larger than toothed whales; in fact, the largest mammal in the world is a baleen – the blue whale.
Other baleen whales include fin whales, minke whales, humpback whales, and gray whales. There are small baleen whales, too – the smallest is the pygmy right whale, which is around 20 feet long. The largest toothed whale is the sperm whale. At an average of 60 feet long, sperm whales are actually the largest toothed animals in the world. The sperm whale is unusual, though, as toothed whales tend to be small. Examples of toothed whales include dolphins, porpoises, narwhal whales, beaked whales, killer whales, pilot whales and beluga whales. The smallest whale in the world is the toothed dwarf sperm whale, otherwise known as the Owen’s pygmy sperm whale. These guys average around 8 feet long, weighing in at around 300 pounds. That makes them even smaller than dolphins.As far as earwax goes, it has only been found in baleen whales. I have found references to earwax in both fin whales and humpback whales. Whale earwax serves a different purpose than our earwax. Its primary job is to prevent water from entering the ear canal, and it is not shed. In fact, baleen whales accumulate layers of wax as they get older; the more layers of earwax, the older the whale. Fin whales add 2 layers of wax a year, while humpback whales add 4. Scientists can use these layers to approximate the age of the whale. Actually, that’s the only way of aging a baleen whale. Toothed whales can be aged by looking at their teeth, because teeth grow in layers. You can count the layers of a whale’s tooth and see how it was. But baleen doesn’t grow that way. So the only way of knowing how old a baleen whale was is by counting the layers of its waxy ear plug.
I wonder if toothed whales also have earwax? They all have ears, which are just holes in the side of their heads immediately behind their eyes. And presumably they all need a way to keep water from flooding their ear canals. Maybe they have some other way of keeping water out of their ears. Or maybe we just haven’t looked hard enough yet?
The images I used were taken from the following sites:
Narwhal whale: http://concise.britannica.com/ebc/art-6694/Narwhal
Blue whale: http://en.wikibooks.org/wiki/Adventist_Youth_Honors_Answer_Book/
Nature/Marine_Mammals
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