Cetacea :

1. Cetacea: Whales and Dolphins http://www.compusult.nf.ca/ditt/sounds/hump.wav

2. Whales and dolphins are mammals. They are NOT fish. • They bear live young. (They don’t lay eggs.) • They breath through lungs. (They don’t have gills). • They live in the ocean. Some dophins live in rivers. • Mother whales and dolphins give milk to their babies. • They are warm blooded (body temperature stays constant. It doesn’t change.)

3. There are two kinds of whales: Baleen whales: like the humpback whale and blue whale. These whales have a comb-like structures in their mouth that they use to “sweep” the water of plankton and krill. Toothed whales: like the sperm whale, orcas, and dolphins. These whales use their teeth to catch their prey. They DON’T chew it, however. They swallow it whole.

4. Dolphins are toothed whales. They are divided into two groups: Dolphins: they have longer heads, with a long “beak.” Porpoises: they have small heads without a “beak.”

5. Dolphins live and travel in groups called pods. Dolphins communicate with a series of clicks, whistles, and whirrs. Scientists are trying to understand the complex relationships between dolphins. A group of dolphins have been known to protect a member of the pod when it is in danger. Sometimes they can also protect humans stranded at sea.

6. Whale and Dolphin’s bodies are made for life in the ocean. • “bullet-shaped” body. This shape allows them to swim swiftly. • They have a fluke or tail, that they move up and down to push themselves forward. • They have two pectoral flippers that allow them to stir in the direction they want to go. • They don’t have hair or fur like other mammals. • They have a special layer of fat, called “blubber” that allows them to stay warm in cold water. • They have one or They have a streamlined two blowholes that they use to breath.

7. Whales also live in pods. • An adult male whale is called a bull. • An adult female whale is called a cow. • A baby whale is called a calf. • Mother whales have only one baby at a time. • They give birth to their babies live. • They feed them milk until they can feed on their own.

8. Dolphins use a hunting system called echolocation. • A dolphin has a special organ called a “melon.” • With its melon, a dolphin can produce sounds that he sends out into the water • When the sound hits a target, such a school of fish, it bounces back. • The dolphin then can figure out how far away the target is. • The U.S. Navy has used dolphin echolocation or sonar to find underwater mines.

9. Whales and dolphins breath through blowholes. • Blowholes are located on top of their heads. • Toothed whales (including dolphins) have only one blowhole. • Baleen whales have two blowholes. • When whales come out of water they inhale air. • When whales exhale they also shoot out a wet midst, called a spout.

10. Humpback and blue whales do not have teeth. • They are called balleen whales. • Baleen, are long, hair-lined plates inside a baleen whale’s mouth. They help the whale catch prey. • As the whale swims forward, water filters through its open mouth. • When the whale closes its mouth, the water is forced out, and tiny creatures are trapped inside the baleen.

11. Moving in Water • Orcas and other whales jump out of the water and do a flip. • This behavior is called “breaching.” • No one knows exactly why they do it. • Dolphins can leap out of water. • They can often be seen riding the currents of water made by motor boats. • The dusky dolphin can leap up to 17 feet into the air.

12. Whale Records • The largest animal in the world is the Blue Whale. It’s even bigger than the largest dinosaur that ever lived! • The sperm whale is the biggest toothed whale. • It can dive up to 10,000 feet into the water. • A blue whale can eat up to 40 tons of krill in one day! • A baby blue whale weighs 12 to 15 tons at birth.

13. Comparing size of whales

14. Humans and Whales • From the 1600s to the early 20th century whales were hunted. • At first they were hunted for their meat and bones. • In the 1900s they were hunted to turn their blubber into oil for lamps. • Whales were almost killed off. • Today most whales are protected by environmental laws.

15. Whales in Danger • Although whales are protected by laws today. • Many whales are dying because of pollution and environmental causes. • When whales become sick they “beach” themselves. • No one is sure why they do that. • Whales can also become stranded into rivers and bays, like Humphrey the whale in the 1990s. • Whales can also get caught in fishing nets. When this happens they can die, unless they are released again.

16. What are some other ways that we can protect whales? What will you do?