Had
been to Konkan for a vacation last year. It was a beautiful winter morning. At
a point in the ghats, we stopped at a tea stall to enjoy the view with a glass
of hot chai.
As
we chatted with the chaiwalla, he told us the story of the fisherman who saw
dolphins in the sea a few years ago. As this news spread, these dolphins became
a tourist attraction. Now, many launches are available that take tourists into
the sea to see these animals of titanic fame.
We
decided to go too! The sea was rough, and the boat rocked. But we continued
undaunted. The boatman pointed out into the sea. And lo and behold – we could
see a dolphin jump out of the water and back into it….several times. Oh! What a
beautiful sight!
But
have we ever wondered – what makes these ‘fish’ come out of water?
And
not only dolphins, even whales show this behavior. Why?
The
answer lies in the basic fact that dolphins and whales, although often mistaken
to be, are not fish. So, unlike fish, they do not breathe underwater through
gills. They are mammals, and like humans, have lungs for breathing. They do not
take in the oxygen dissolved in water, like fish. They breathe oxygen from air.
We
cannot hold our breath underwater for a long time. We have to come to the
surface of water to breathe in again, unless we are carrying oxygen cylinders.
Similarly, the dolphin comes to the surface of water to breathe air through a
hole on its back that functions as a nostril. It takes in sufficient amount of
air into the lungs and goes underwater again. It can stay underwater for about
fifteen minutes. Whales breathe the same way, but some of them can remain
underwater for upto an hour!
But
doesn’t the water enter the lungs of these animals and choke them? No – at the
base of their breathing hole, they have a flap which closes as they dive. This
flap keeps the water out of the lungs. Also, as they go deeper, although the
pressure of the surrounding water increases, their lungs collapse, and the
water is kept out.
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