Sharks have existed for over 420 million years, predating dinosaurs. They have powerful jaws that can move both vertically and horizontally. While some sharks hunt alone, the presence of one feeding shark can attract others to feed as well. The largest shark species like the whale shark and basking shark are filter feeders rather than predators. Great white sharks, tiger sharks, hammerheads, and bull sharks are among the most dangerous predatory sharks. Sharks have highly developed senses, with two-thirds of their brain dedicated to smell, vibration detection, and electromagnetic field detection, which helps them hunt prey efficiently.

1. Sharks Sharks ( Selachimorpha) The earliest known sharks date back far as 420 million years ago. That’s before the Dinosaurs. Sharks were called “sea Dogs” by sailors until the 16 th century. The name Shark was first used by Sir John Hawkins when he exhibited a specimen in London in 1569.

2. Sharks Teeth Sharks have the most powerful jaws on the planet. Unlike most animals jaws, both the sharks upper and lower jaws move. Sharks have 5 to 15 rows of teeth in each jaw .

3. Dinner Time Usually Sharks eat alone. But sometimes one feeding shark attracts others . They will bite at almost anything that gets in their way – even each other.

4. Gentle Giants Not all sharks are carnivores Funny as it may sound the most harmless sharks tend to be the biggest. They are the Whale Shark, Basking Shark, Megamouth Shark. They all have a diet of shrimp and plankton.

5. Dangerous Predators The Great White , Tiger, Hammerhead, Mako and the Bull Shark are the biggest Predators. About 100 shark attacks each year. 10 result in human deaths. In perspective people kill thousands of sharks in one year . For instance Shark Fin Soup Shark Steaks. The most popular shark in the U.S.A is the Mako. Now who is the most dangerous predator ?

6. Super senses Why are Sharks so successful Predators? A Shark uses two – thirds of its brain for its senses :- smell. They feel vibrations in the water by using a line of canals that go from the head to the tail. Called a “lateral line”. They also have a sensory organ known has the “ Ampullae of Lorenzini”. Ampullae detects the electric field of its prey.

7. A few less known Sharks The Sand Tiger Shark 10 feet long. Hunts at night.

8. Wobbegong Shark Grows about 8 feet long (2.4mths). Lies at the bottom of the sea. It has a worm like projections on its head to attract its prey

9. Zebra Shark You can keep this gentle small shark in aquariums. The tail of this shark is half its length of its body.

10. Shark sizes

11. The end Well I hope you have enjoyed my slides show on Sharks. I would like to take a couple of minutes more of your time to watch a short video.

12. Sources http:// www.kidzone.ws/sharks/index.htm http://www.flickr.com/photos/johnpamowens/83293310/sizes/s http://search.creativecommons.org/?q=great+white+shark&sourceid=Mozilla-search http:// search.creativecommons.org/?q = sand+tiger+shark&sourceid =Mozilla-search# http://www.flickr.com/photos/rling/3246660564 http:// en.wikipedia.org /wiki/Sharks http:// search.creativecommons.org/?q = sharks&sourceid =Mozilla-search