In the world's great whale tales, including Herman Melville's "Moby Dick," the storytellers are preoccupied with one particular whale attribute: awesome size. Many whale species are staggeringly enormous. The blue whale, for example, can grow to 100 feet (30 m) long, about the height of a 10-story building, and can weigh as much as 150 tons (300,000 lb or 136077.7 kg). Its
heart alone is the size of a small
car, and there's enough room on its tongue for 50 people. It is the largest known animal in
Earth's history.
But despite their monumental proportions, the most phenomenal thing about whales isn't how big they are: It's the way they live. Whales are
mammals -- warm-blooded, air-breathing creatures -- but they spend their entire life in the ocean. In this article, we'll look at the remarkable adaptations that make this possible. We'll also explore the mysterious behavior of whales, and we'll investigate the history of commercial whaling and whale conservation.
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New Species
In 2003, Japanese scientists reported that they had discovered a new whale species, based on DNA analysis of nine whale carcasses. Eight of the carcasses date back to 1970. At the time, researchers believed they were small fin whales. In examining a new carcass collected in 1998, scientists suspected they had an unidentified species.
Click here to get the story.
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Whales are mammals, just like us, and more than 50 million years ago, their ancestors walked on land as we do. It's not clear what these animals were like, but some paleontologists believe they may have been hoofed mammals, something like modern cows. Other paleontologists believe that whales were more like modern wolves. Over the course of millions of years, the ancient creatures spent more and more time in the water, living partly on land and partly in the sea, like modern sea lions or otters. Eventually, the creatures stopped climbing onto land altogether, and they slowly lost their now-useless legs and fur. The evidence for this hypothesis is fairly compelling: Paleontologists have even found fossilized whale-like creatures with legs so small that they couldn't possibly support the animal's weight.
Photo courtesy Iain Kerr, Ocean Alliance
A humpback whale, one of the most magnificent whale
species. Humpbacks are known for their intelligence, playfulness and
elaborate vocalizations.
See more pictures of whales.Take the quiz
How well do you know belugas, bowheads, and narwhals? Check out this quiz from Animal Planet:
Whale Quiz |
Modern whales have wide
tail flukes,
extended flippers and, in some species,
dorsal fins. Whales swim forward by flexing their tails up and down, instead of side to side as with most fish. To change direction, they move their flippers, similar to the way an
airplane steers (read
How Sharks Work for details). The dorsal fins, if present, serve to stabilize the whale's body as it swims.
In the next section we'll look at how the whale made the transition from land to water.
Animal Planet
Whales aren't the only mammals that live in the water. Otters spend lots of time in rivers and oceans, and their bodies are adapted for moving smoothly through water. Dolphins are aquatic mammals, too. You can learn more in this mammal guide and from Animal Planet.
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