Many people are frightened by sharks.
They usually think that sharks are "dangerous killer". In fact, there are
about 340 different kinds of sharks in the world, but fewer than 40 of
them are dangerous to human. Although some sharks are very aggressive,
the danger from sharks is much smaller than most people think.
Most of the sharks have hundreds or even thousands of shark teeth. These are arranged in rows of four or more, and are set quite loosely in the jaw. Sharks get a new set of teeth every two weeks. So the sharks can have sharp teeth to eat the food. Sharks usually eat small fish in the sea. When there isn't much food around, sharks will eat almost anything, including smaller sharks and even rubbish.
A shark's sense of smell is very sharp. It can follow the smell of blood across miles the ocean. They can see very well and they have excellent hearing. Sharks can also feel movements in the water very easily, and they can detect a fish moving as far as 30 metres away. So, if you have a wound in your body, it is better not to go swimming.
Now, let's look at the different
types of sharks:
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The followings are some useful homepages for sharks:
1.Hammerhead
shark
The Hammerhead shark is one
of the strangest looking sharks in the world. It has
a head that is shaped like a hammer, and its eyes are on either end of
the "hammer".There are two species of Hammerhead Shark usually seen by
Australian divers. They are the Scalloped Hammerhead and the Great Hammerhead
. The Scalloped grows to about 350cm while the Great Hammerhead can grow
to about 6 metres. The largest ever accurately measured was 18.3 feet/5.6
metres and weighed more than 1,000 pounds/454Kg. Their appearance tends
to scare people much more than any actual aggressive sharks.
Related URL Link of Hammerhead shark
2.The
Great White shark
The Great White shark has
a huge mouth. There is a grey-blue colour on top and white underneath the
shark. The Great White shark is the most dangerous shark.
Great Whites were always thought to
be the king of the seas. No animal attacked the Great White according to
the experts.The Great White gives birth to live young unlike many other
sharks that lay eggs. The newly born shark gets no help from the mother
and must fend for itself. A newborn Great White is believed to be around
four feet long from unborn sharks found in a pregnant female.They were
just like a miniature Great White and bigger than a lot of sharks are when
adult. The smallest White shark ever caught was 47" long and thought to
be newly born. They grow about 10"/25cm each year and reach maturity in
about 10 years.
Related URL Link of
the
Great White shark
3.The
Tiger shark
The Tiger shark has stripes
along its body. It is fast and dangerous. It is like a tiger on land. So
it is called the Tiger shark. Tiger sharks often come into Hong Kong waters
around late May and early June. The largest Tiger shark ever caught was
9.1 metres long. Tiger Sharks grow very big and can
be very dangerous. They are responsible for a large number of human deaths.They
are most common in warmer water.
Although some adults will stay in one area they are also known to be able to move hundreds of kilometres. Young sharks have the very distinctive tiger stripes but in very large specimens they may not be present. They have strong, serrated upper teeth but instead of being triangular they are hooked or cockcomb shaped. That means the point is not straight down but turned to the side.
This shark has been known to come into very shallow water, sometimes with most of their body exposed and they have also been found as deep as 150 metres. The Tiger can get extremely large up to 6 metres, maybe more. Seems to prefer the deep water out to sea during the day and will come in close to reefs and the shoreline at night. It will sometimes also come in close to shore during daytime.
Related URL Link of
the
Tiger shark
4.The
Whale shark
The Whale shark is the largest
shark in the world. It grows up to16 metres in length and weighs as much
as six big cars put together. The
Whale Shark is a giant but luckily a gentle giant. It can grow to 18 metres
or more (60 feet). It is usually a dark colour with whitish spots covering
the entire body. In Australia it can be found in the far northern waters
of Queensland and New Guinea but is more common in the Indian Ocean off
Western Australia. Ningarloo Reef in W.A. has become famous for attracting
these massive creatures and divers come from around the world to see them.
Related URL Link of the
Whale shark
5.The
Blue shark
The Blue shark is dark blue
in colour. It is very fast and dangerous.
It is sometimes called a
Blue Pointer in Australia. (The Mako has also been called a Blue pointer
in Australia and these local terms can be confusing).This is a long thin
shark that can be very fast in the water. It is easily identified with
a rich indigo blue upper body and a white lower body. It has a very long
narrow nose and very long, slender pectoral fins. The second dorsal fin
is small. Whaler tail. It has thin triangular upper teeth with a slight
serration and a slight hook to them. It can grow to nearly 4 metres.
Related URL Link of
the
Blue shark
BYE!