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  • Here are some facts about great white sharks: white sharks are live-birthed, usually in

  • litters of between four and seven individuals.

  • Now they're called pups, but when they're born they're between 1.2 and 1.5 meters!

  • So that's a pretty big baby.

  • It takes a great white shark about ten to twelve years to reach maturity at which point

  • the females are actually about a meter longer than the males - the largest recorded being

  • over six meters - roughly the size of this red boat behind me.

  • At this length they'd weigh about two to three thousand kilograms.

  • Oh man!

  • Now there are stories of some great whites being over seven meters but those are unsubstantiated.

  • White sharks are warm bodied.

  • They're not warm-blooded like us - they can't maintain a perfectly stable temperature, but

  • their internal organs are kept at up to thirteen degrees above the average temperature of the

  • ambient water around them.

  • The heat generated by their muscles is actually transferred to the blood in their veins as

  • it returns from the shark's extremities, so it warms it up and keeps the core temperature

  • a little bit hotter.

  • This allows the shark to venture into colder waters and also to have explosive power.

  • Its muscles work a lot better when warm than when cold, just like ours.

  • The tradeoff is the shark requires about ten times as much energy as if it didn't heat

  • its body and that's why they need to feed on these blubber-rich seals and whale carcasses.

  • White sharks like to hunt when it's light out because they use their eyesight to spot

  • their prey.

  • But when they open their jaws, their eyes actually roll back into their head to protect

  • them and so they're actually blind when they're taking a bite.

  • Now they do like conditions that are a little low visibility because they rely on stealth

  • to track down their prey.

  • If a seal spots them coming, it's basically game over because the seal is so much more

  • maneuverable and it can definitely get away from the shark.

  • But they only eat sea mammals after they're about 2.5 meters long, which is why most of

  • the sharks we're seeing around here are quite large.

  • Before that, they're diet consists mainly of fish.

  • The gestation period is thought to be about eighteen months and that leads to a two to

  • three year reproduction cycle and with such small litters that means it takes a long time

  • for this shark population to recover.

  • There are a couple misconceptions about great white sharks.

  • One is that they can't get cancer and that's led to a lot of people hunting them down and

  • trying to use their fins as an anti-cancer soup.

  • But in reality sharks get cancer just like anything else and there is photographic evidence

  • of sharks with big tumors so it makes no sense to hunt down sharks as a cancer remedy because

  • they get cancer just like we do.

  • Another misconception is sharks are coastal creatures that just cruise the beaches waiting

  • to bite people.

  • In reality the sharks spend much of their time way, way out at sea and very deep, over

  • a kilometer deep.

  • It's kind of shocking but we've only found this out in the last couple of years so there

  • is so much about sharks that remains undiscovered.

  • We don't know where they go or what they do for most of the time that they're alive.

  • That's why research projects like this are so important to find out more about the shark

  • and figure out how we can help it rehabilitate and become the predator of the sea that it

  • once was.

Here are some facts about great white sharks: white sharks are live-birthed, usually in


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ホオジロザメについての10の事実 (10 Facts About Great White Sharks)

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    林宜悉 に公開 2021 年 01 月 14 日