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Slow moving and calm, easy to recognize by the pattern of white spots on its body and
its wide, flat head, the whale shark is a secretive ocean wanderer.
Compared to other sharks, very little is known about this mysterious and elusive creature,
a gentle giant of the ocean.
Despite its name, the whale shark is not a mammal.
It is a shark!
The whale shark is the largest living species of shark, as well as the largest fish of any
kind in the world.
The largest whale shark to be measured was more than 41 feet or 12 meters long.
The only animals on earth more massive than whale sharks are whales.
Like many whale species, the whale shark is a filter feeder, skimming food like fish eggs,
plankton, krill, and small fish from the water with its huge, gulping mouth.
The mouth of a whale shark can be nearly five feet or 1.5 meters across, easily large enough
to catch a human, but they are so gentle that divers can swim around them without fear.
Like other sharks, whale sharks have row after row of teeth - hundreds of rows, in fact,
for a total of about three thousand teeth.
Unlike the teeth of most sharks, these teeth are so tiny you can barely see them, and they
do not use them to eat.
To feed, the whale shark sucks in huge amounts of ocean water, then closes its mouth and
pushes the water out through its gills.
Structures in the gills act like strainers, catching anything solid for the whale shark
to swallow.
Only three species of shark, including the whale shark, are known to eat by filter feeding.
Whale sharks can be found in warm and tropical waters around the world.
They swim thousands of miles each year looking for food - often alone, but when there is
enough food, many whale sharks may school together to feed.
Scientists believe that whale sharks proably use their sense of smell to find food.
They spend most of their time near the surface, where their favorite foods can be found, but
will sometimes dive deep down for reasons scientists do not yet understand.
There are many things that scientists do not know for sure about whale sharks, including
how long they live - although it is probably somwhere between 70 and 100 years.
No one has ever seen whale sharks mate or give birth.
From whale sharks that have been caught, we know that female whale sharks lay eggs inside
themselves, where they hatch, and then the baby sharks are born alive.
Although young whale sharks may be eaten by anything that can catch them, full-grown whale
sharks have no natural predators.
People have caught whale sharks for food, but increasingly laws are being made to protect
whale sharks and ban fishing for them.
For one thing, whale sharks are increasingly valuable alive, as a tourist attraction.
People love to swim with the huge, gentle sharks, and will come from all over the world
to visit places that whale sharks are known to be found.
A few aquariums even have whale shark exhibits where people can view these huge fish, but
because of their size and special food requirements, whale sharks are tricky to keep in captivity.
It is difficult to count the number of whale sharks in the ocean, but they are considered
endangered.
Whether they are caught by fishermen, tangled in fishing nets by accident, or struck by
boats, these slow-growing fish are at risk, and their populations are shrinking.
People are working hard to protect whale sharks, passing laws to ban fishing for them and improving
fishing techniques so they won't get caught by accident.
If we ever hope to unravel the mysteries of the whale sharks, we must protect them so
that they can continue to travel the ocean.
I hope you enjoyed learning about whale sharks today, the gentle giants of the ocean.
Goodbye till next time!