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SK1 |
In some form, sharks have been
around for about 400 million years. |
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SK2 |
Even before dinosaurs roamed the earth,
sharks hunted through the oceans! |
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SK3 |
They're such good survivors that sharks
have had little need to evolve in the last 150 million
years. |
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SK4 |
Almost all sharks are "carnivores"
or meat eaters. They live on a diet of fish and sea mammals
(like dolphins and seals) and even such prey as turtles
and seagulls. |
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SK5 |
Sharks even eat other sharks. For example,
a tiger shark might eat a bull shark, a bull shark might
eat a blacktip shark and a blacktip shark might eat a
dogfish shark! |
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SK6 |
The teeth of the carnivores are sharp and
pointy. Their skeleton is made of cartilage instead of
bone, which allows greater flexibility. |
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SK7 |
Their skin is made of denticles instead
of ordinary fish scales. The denticles are constructed
like hard, sharp teeth and help to protect the shark from
injury. |
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SK8 |
Some sharks have eyes similar to a cat.
A mirror-like layer in their eyes allows them to see better
in the water. This allows the shark to hunt in clear seas
or murky water. |
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SK9 |
One of the reasons that sharks
are such successful predators is that they have such super
senses. Two-thirds of a shark's brain is dedicated to
its keenest sense -- smell. |
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SK10 |
Normally, sharks eat alone. But sometimes
one feeding shark attracts others. They swim up as quickly
as possible and all begin to try to get a piece of the
prey. They bite wildly at anything that gets in their
way -- even each other. |
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SK11 |
Not all sharks are fierce carnivores. Some
are quite harmless. Oddly enough, the most harmless sharks
tend to be the largest! The basking shark, the whale shark
and the megamouth sharks all fit this description. |
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SK12 |
Sharks have a few unusual senses.
They are able to feel vibrations in the water using a
line of canals that go from its head to its tail. |
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SK13 |
The most dangerous sharks are the Great
White shark, the Tiger shark, the Hammerhead shark, the
Mako shark and the Bull shark. |
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SK14 |
On average, there are only about 100 shark
attacks each year and only 10 of those result in a human
death. |
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SK15 |
Hammerheads are fierce predators that use
their great sense of smell to find prey. They eat fish,
including rays and other sharks, as well as octopuses,
squid and crustaceans. |
