What swims in the ocean and looks like a fish but is not a fish? If you said a whale, you would be correct.
A whale is a mammal, the same as you are. It has lungs and breathes air, is warm-blooded, and its body temperature stays pretty much the same all the time. Yet a whale is perfectly adapted to life under the sea.
Whales are divided into two groups â€” baleen and toothed. Toothed whales are intelligent animals that cooperate with each other to hunt in a way similar to lions or wolves. They use their teeth to capture prey, but not to chew it. Some toothed whales can swallow up to 50 pounds of meat whole.
Baleen whales do not have teeth; instead, their upper jaws are rimmed by a fringed, comb-like apparatus called baleen. Baleen whales take in huge amounts of water and filter it out again through the baleen. As many as 100 pounds of microscopic plankton is caught this way with every huge gulp; blue whales can eat 9,000 pounds of plankton in a single day.
Baleen whales mostly eat organisms that are 100 million times smaller than themselves â€” plankton. The largest of the plankton are krill, which grow (at most) to two inches in length. Baleen whales will also eat small fish.
Toothed whales prefer seals, fish, and squid, but will also eat other whales â€” and have even been known to catch unwary polar bears!
Baby whales are born underwater. As soon as the baby emerges, the mother helps it to the surface for its first breath of air. Shortly after birth, the calf starts to take milk from its mother. The milk is very rich, and baby whales grow very fast. Very young blue whales can gain 10 pounds an hour!
Whales are found in tropical lagoons, the Arctic Ocean, deep ocean canyons, coastal reefs, and even in fresh water rivers in China. Their diversity guarantees that as long as people leave them alone, whales will survive-and thrive-throughout the worldâ€™s oceans.
For hundreds of years, people have hunted and killed these intelligent marine mammals for their meat and oil. Many species are close to extinction. Today whales are protected by the Marine Mammal Protection Act of the US, and by conservation groups around the world.