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The whale is an extremely huge sea animal. The blue
whale is considered the largest creature on Earth today.
In fact, the blue whale is much bigger than the
prehistoric dinosaurs, some of which weighed almost 50
tons. The estimated weight of the blue whale is twice
that of the dinosaurs and it can grow to lengths of 100
feet or more. The whale looks very much like a huge
fish. Contrary to popular belief, the whale is not a
fish but a mammal which has adapted itself to living
permanently in water. All whales can be divided into two
groups : the baleen whales and the toothed whales.
The baleen whales do not have teeth. Instead, they
have enormous whalebone sieves known as baleens in their
mouths to strain the tiny organisms that they swallow
when they close their mouths. The blue whale is an
example of a baleen whale. The huge blue whale feeds on
tiny sea creatures such as small fishes and shrimps.
Female baleen whales are always larger than the males.
The toothed whales, as their name suggests, have
teeth in their mouths. Examples of toothed whales
are the sperm whales and the killer whales. The sperm
whale is the largest member of the toothed whale family.
It is called such due to the valuable sperm oil deposit
found in its head. At one
time, the sperm whale was widely hunted for this oil
which was used to make candles. The sperm whale feeds on
giant squids, fish and even other sharks. It is quite
aggressive by nature but is not as fierce as the killer
whale. Killer whales have been known to charge at boats
without provocation. They feed on seals, porpoises,
polar bears and walruses. When there is a shortage of
food, the killer whales will even attack much larger
whales. In terms of size, the toothed whales are
opposite to the baleen whales, with the males being
larger.
Although whales live in water, these mammals breathe
in air through their lungs. A whale takes in oxygen when
it is at the surface of the water. with this supply of
oxygen, it can remain under water for more than an hour.
When it resurfaces to replenish its supply of air, it
will discharge the used air from its lungs with a
tremendous force. the air that is discharged will rise
to a great height due to this force. a column of steam
or spray is formed as the whale exhales. this is because
the air from the whale's lungs is saturated with water
vapor at a higher temperature and the cold air outside
condenses this vapor. Sometimes, a whale may 'blow'
before its nostrils are completely above the surface of
the water. When this
happens, the sea water is also forced out with the
exhaled air and it gushes up like a fountain.
All species of whales give birth to their young
alive, usually one at a time. Some of these baby whales
are gargantuan. A blue whale at birth weighs something
like four tons. Whales suckle their young just like
other mammals. A baby blue whale is capable of drinking
half a ton of its mother's rich, thick milk.
Although whales are massive in size, they are one of
the most graceful animals in the oceans. Unfortunately,
like many animals on Earth, whales are in danger of
extinction. For many years, man has hunted them for oil
and other materials. This has steadily dwindled their
numbers. Sometimes, we also hear of hundreds of whales
being stranded on beaches and suffocating to death.
Without the buoyancy of water, their great weight
crushes their lungs and kills them. In an effort to curb
extinction, many governments have banned whaling and
have taken positive steps towards the conservation of
whales. |
