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It's the size of a whale but it's actually the world's largest fish! I'm Jonathan Bird
and this is shark academy!
Well as shark experts of course you all know that sharks are fish. The whale shark is not
only the world's largest shark…it's the world's largest fish, and it's called a whale
shark because it's the size of a whale. It's not a whale. It's not related to whales. Whales
breath air. They are mammals. Sharks are fish. So the whale shark is a fish the size of a
whale.
The whale shark is really big! We're talking: they reach fifty feet long. That's the length
of two school buses end to end. So this is a very very large fish. How does it get so
big? Well, it eats a lot. But you might be surprised what it eats. Whale sharks survive
almost exclusively on plankton and small fish. A whale shark feeds by swimming through the
water with its mouth wide open, scooping in vast quantities of water. The water goes into
the back of the throat and it goes back out through the gills. But on the gills are little
combs called gill rakers and they're filters. What happens is the plankton gets stuck in
the filters when the water goes through and then every once in a while the shark closes
his mouth and swallows all the plankton down. So the whale shark is completely harmless
to people, even if a person went into its mouth, it wouldn't be able to swallow you
because it only has a throat about this big. The throat is designed for swallowing small
things, little fish, plankton, not people. Completely harmless to people.
The only way a whale shark could hurt you is if someone dropped one on you, or maybe
if it hit you with its tail. But I don't know anybody stupid enough to get hit with the
tail of a whale shark.
One of the most interesting characteristics of the whale shark is its skin pattern. It
has sort of a polka-dotted stripey pattern that almost looks like dominoes. In fact in
some countries they're called the Domino shark. Nobody's quite sure what this coloration pattern
is for, the best guess is that it helps with that dappling of light near the surface, it
almost helps create a sort of camouflage on their back. But why would they need camouflage,
are they sneaking up on the plankton? Nobody really knows.
So since the whale shark is so humongous, you would expect that it would have a pretty
large babies. Actually it doesn't. The pups are born only about a foot long. Because they're
so small the female can give birth to over three hundred pups at a time. A female whale
shark can't produce babies until she's thirty years old, so it takes a long time for all
those pups to grow up. So even though the whale shark has a lot of pups, they're still
vulnerable to over-fishing.
If you want to learn more about whale sharks, check out the link below, my adventure filming
whale sharks in Mexico! If you're on Facebook or Twitter check out the links right here,
become a fan, we'd love to hear from you. And if you want to tell us something about
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and this is Shark Academy!