Transcript of Shark slides
- 1. Sharks there are more than 400 species of these meat-eating
fish. And one of the most dangerous of these is the great white
shark.
- 2. The great white usually lives in cool, coastal waters, such
as those off the shores of Australia and South Africa. However,
scientists now believe the great white may also be an open-ocean
dweller.
- 3. The great white can grow to more than 21 feet long and can
weigh more than 4500 pounds. It can swim at speeds of up to 43
miles per hour.
- 4. Great whites are ovoviviparous, which means that the eggs
hatch inside the mother sharks uterus and continue growing inside
her until theyre born.
- 5. After theyre born, baby sharks swim away from their mothers
because their mothers dont care for them and sometimes will even
eat them. Many shark babies dont live past a year.
- 6. Great whites grow slowly and dont mature until theyre 12-18
years old,
but they can
live to be over 30 years old.
- 7. Like all other sharks,
the great white is cartilaginous, which means its skeleton is
made of cartilage
instead of bone.
- 8. Most fish have swim bladders that allow them to remain in
one place without sinking, but sharks dont.
- 9. Instead, sharks have oil in their livers that weighs less
than water and helps keep them from sinking. Still, sharks must
swim constantly.
- 10. Great whites have warm blood and warm muscles, which makes
them faster and stronger than other sharks.
- 11. A white underside and gray dorsal area make the great
whites color look mottled, which makes it difficult for their prey
to spot them.
- 12. Their large cone-shaped snouts and torpedo-shaped bodies
help the great white to swim, and their skin, which is made up of
teeth-shaped scales, is so rough its been used as
sandpaper.
- 13. Great whites are very curious and intelligent animals. In
fact, theyre only one of a few types of sharks that actually lift
their heads above the water to see their prey.
- 14. Some believe a shark can smell better this way since odors
travel faster in air than in water.
- 15. The great whites most amazing feature is its teeth. With a
length of up to 2.5 inches, the great whites teeth are sharp and
triangular with jagged edges, so they can tear hunks of meat from
their prey.
- 16. Serrated teeth are located behind the normal teeth so that
when those teeth break off, they can be replaced easily.
Great whites can have 3000 teeth at one time!
- 17. Sharks are considered apex predators, because they eat
mostly animals lower on the food chain and arent often preyed upon
by other animals.
- 18. Seals, sea lions, and dolphins are some of the great whites
favorite foods, but it will also eat fish, whales and even other
sharks.
- 19. It has also been known to eat things it cant
digest.
- 20. The great white has a sixth sense that allows him to detect
electromagnetic fields that are emitted by even the slightest
movement of his prey.
- 21. When it attacks, the great white will swim upward at a fast
speed and then burst out of the water. This is called a
breach.
- 22. Instead of chewing, great whites rip off hunks of flesh.
And, after eating a large meal, a great white can last a month or
two without additional food.
- 23. Great whites are infamous for attacks on humans, however
there are less than 80 attacks reported each year.
- 24. Scientists think great whites attack humans because people
either swim or float close to the surface and to the sharks, they
look like seals.
- 25. Many people survive great white attacks because the shark
will bite once and then back away to let his victim bleed to death
and to avoid teeth and claw injuries from his prey.
- 26. When the shark backs away, humans have a chance to swim to
safety.
- 27. Sharks that attack humans appear to either not like the
taste of them or find the taste unfamiliar. Humans are generally
too bony and sharks like fat.
- 28. In addition, great whites often grab unfamiliar objects in
order to identify them.
Consequently, many human attacks are really just test
bites.
- 29. In spite of shark attacks, cage diving and swimming with
sharks has become a very popular tourist activity in Australia and
South Africa.
- 30. Divers chum the water with pieces of fish as they wait in a
cage for the sharks so they can see them up close and
personal!
- 31. Great white sharks are dangerous but awesome animals.
And, they will always command respect from the other creatures of
the oceans.
- 32. Lets watch as a hungry shark goes after some meat being
dragged behind a boat