Slide 1 Sharks! What do you know about sharks? What would you like to learn about them? What animals do you think of when you think about animals that lived a long, long time ago? Many people think about the dinosaurs that roamed Earth over two million years ago. But guess what? Sharks lived even prior to the dinosaurs! Sharks are ancient animals that have been swimming in the seas for over 400 million years. All sharks are fish, but they are different from other fish in some ways. Sharks do not have bones. They have cartilage. Cartilage is a strong, flexible part of the body, like what you have in your ears. Most sharks have mouths that are filled with rows of sharp teeth. If one tooth falls out, another moves forward to take its place. Sharks can go through thousands of teeth in a lifetime!

Slide 2 Sharks! (Cont.) There are more than 350 kinds of sharks. They live in oceans all over the world. A few sharks can even live in rivers. Some sharks are ruthless. You probably would not want to bump into one of these dangerous sharks when you are swimming in the ocean! Other sharks, though, are harmless. Some people like to swim along with these gentle creatures. The most feared shark is, perhaps, the great white shark. This dangerous shark can grow up to 25 feet long. It can weigh up to 4,500 pounds. It has huge jaws and sharp teeth. Another dangerous shark is the hammerhead shark. It is a powerful swimmer. The hammerhead shark has an unusual head. The shark’s eyes are on each side of its hammer-shaped head. The fierce tiger shark has stripes like a tiger. It hunts as fiercely as a tiger, too. You would not want to be a fish or an ocean turtle when a hungry tiger shark is swimming by.

Slide 3 Sharks! (Cont.) The biggest fish in the sea is the whale shark. It can grow to be 50 feet long and weigh as much as 15 tons. That’s the same weight as 6 big cars! Although a whale shark is an immense shark, it is not a ruthless one. In fact, it is like a gentle giant. People have grabbed on to the backs of whale sharks and swum with them! Another harmless shark is the basking shark. This is the second largest fish. Like the whale shark, the basking shark eats plankton, which is a mixture of tiny animals and plants. In 1976, scientists discovered a new kind of harmless shark, the megamouth shark. The megamouth has a gigantic mouth. Light shines from a megamouth’s mouth. Scientists think that the light attracts plankton for the megamouth to eat. Since 1976, more than 30 megamouths have been discovered.

Slide 4 Sharks! (Cont.) Scientists have learned a lot about sharks. Sharks have a great sense of smell and can smell food from very far away. Sharks feel movements in the water. That helps them fi nd food. Sharks can hear sounds from thousands of feet away and have excellent eyesight. All these senses have helped sharks survive. These days, scientists use small submarines to study sharks that live very deep in the sea. These submarines have remote-controlled cameras that help scientists research sharks. In this way, scientists have learned about sharks such as the tiny dwarf dogshark. Scientists think these sharks hunt in packs, like wild dogs. Another deepwater shark is the green-eyed cookie-cutter shark. These sharks take cookie-shaped bites from the fish they hunt. Sharks have survived for over 400 million years. Will they survive for millions more? People are sharks’ biggest enemies. They hunt and kill over one million sharks each year. Scientists hope that people will learn to respect and protect sharks so sharks can survive millions of years more! Unit 5, Week 3 Sharks! 1. What enemies does a mouse have? 2. Which animals seem fierce to you? 3. Which part of your body is flexible, your bones or your ears? 4. Which of these is gigantic, a mountain, a mouse, an elephant, a whale, or a ball? 5. What animals are harmless? Why? 6. What immense animals live in the ocean? 7. What is something that you did prior to coming to school this morning? 8. What topic would you like to research? Why? 9. Why do some people have respect for spiders? 10. Do dogs roam around your neighborhood by themselves or do they have to be on leashes? 11. What animals might be ruthless when they are hunting for food?