2. Species There are over 360 species of sharks!
They can range in size from small enough to fit in your hand to up to 46 feet!!
Smallest Shark is the Pygmy Shark
Largest Shark is the Whale Shark
Filter feeder, feeds on plankton

3. Whale Shark

4. Skeleton Sharks are cartilaginous fish
Skeleton made of cartilage which is lighter and more flexible than bones

5. Respiration Sharks have uncovered gills used for respiration
Extract oxygen as water passes over the gills

6. Most species of shark can pump water over their gills for when they are not moving using the spiracle
A small percentage of sharks need to stay in constant motion to respire

7. Teeth Sharks teeth are NOT attached to their jaws
Teeth range from needlelike to large flat teeth

8. Teeth are grown and replaced often
Sharks have multiple rows of teeth
Sharks can have about 25,000 to 30,000 teeth in one lifetime
Some replace teeth every
8-10 days, others every few
months

9. Life Span Lifespan varies by species Most live about 20 – 30 years
The spiny dogfish can live up to 100 years
It is thought that the whale shark can live over 100 years as well

10. Sense of Smell Incredible sense of smell
They can detect amounts of blood as small as 1 ppm. (part per million)
Rely on sense of smell to locate prey

11. Locating Prey Lateral lines
Sense organ used to detect motion or vibrations in the water
Electro-receptors
Allow sharks to sense minute electricity caused by muscles and nerves in prey

12. Vision Sharks have eyelids but do not blink
Water surrounding eye cleans it
Sharks have a membrane over eye that protects when being attacked or during predation
Great White Sharks roll eyes back when attacking

13. Do Sharks Sleep?? Scientists unsure!!
Possible they sleep in a similar manner to Dolphins
Half the brain sleeps at a time

14. Why Attack?

15. Shark Attacks 2000 - 79 attacks, 11 fatalities
Majority occur in the United States
More people die from lightning strikes each year

16. Sharks Involved
Three types of sharks have been involved in a significant amount of attacks
Great White
Tiger Shark
Bull Shark

17. Great White Shark
Great Whites are generally about ft and weigh lbs
Found in waters between 54 and 75 degrees F

18. Countershading
White underside and gray dorsal side
Difficult to see when looking at horizontally
When seen from above, gray blends in with the water
When seen from below, white blends in with surface of water

19. Typical Prey
Sting rays, tuna, smaller sharks, dolphins, seals, sea lions
Shark attacks most often occur in the morning, within 2 hours after sunrise
Hard to see a shark close to the bottom
Attack from below at fast speeds

20. Tiger Sharks Average 11 feet and 850 - 2000 lbs
Commonly found around islands in the central Pacific
Dark spots and stripes are prominent in young sharks and fade as the shark matures

21. Hunting Habits Teeth can bite through bone and turtle shells
Known to circle its prey and even study it by prodding it with its snout
Tiger sharks devour their entire prey when attacking

22. Hawaii Tiger sharks have become a problem in Hawaii
Hunted to help control attacks, but no decrease occurred
Considered sacred by native Hawaiians

23. Bull Shark
Dwell in shallow water, possibly posing highest threat to humans
Can tolerate freshwater
Males: 6.8 ft, about 200 lbs
Females: ft, about 700 lbs

24. Hunting Habits Bump and Bite Technique
Shark circles prey often bumping them before the actual attack.
They are extremely territorial and will attack other animals that enter their territory.

25. Why attack? Mistaken Identity:
Shark mistakes a person in the water as a seal when looking from below the waters surface
Curiosity

26. Sharks typically bite once and then swim away
Explanations:
Humans do not taste like their typical prey
Return to the prey after it exhausts itself

27. Dolphin Protection Sharks will not attack when dolphins are around
Scientists unsure why this phenomenon occurs

28. Avoiding an Attack Avoid water during darkness or twilight hours
Do not enter water if bleeding from an open wound
Do not wear shiny jewelry – resembles fish scales
Avoid areas near commercial fishing
Avoid murky waters
Do not splash a lot

29. Fending off an attack
Hit back in sensitive areas such as the eyes and gills
Shows shark you are not defenseless

30. Hammerhead Shark Habitat: Shallow tropical and warm temperature waters
Diet: Stingrays, Other small sharks, fish, crustaceans
Size: ft.
Attacks: 18 (0 fatal)

31. Hammerheads have small mouths and seem to do a lot of bottom-hunting
Hammerheads have small mouths and seem to do a lot of bottom-hunting. (Stingrays!)
Their wide-set eyes give them a better visual range than most other sharks.

32. They are also known to form schools during the day, sometimes in groups of over 100.