字幕列表 影片播放 列印英文字幕 when you think of a shark what do you picture in your mind do you think of a big thing sticking out of the water or maybe a huge set of sharp teeth sharks are some of the most famous animals in the ocean but do you know what makes a shark shark well for one thing all sharks are fish that might not surprise you since they live and swim in the water but sharks are a special kind of fish one of the things that makes them different from other fish like goldfish is that sharks have a special skeleton our skeletons are made of bone and so are the skeletons of most kinds of fish but a shark skeleton isn't made of bone it's made of cartilage and you have cartilage in your body to you can feel it right now touch the tip of your nose wiggling around how's it feel what about your ear can you bend it you're sure cam because the tip of your nose and your ear aren't filled with bone they're filled with cartilage cartilage is a lot lighter than bone and it bends easily so having a skeleton made of this stuff help sharks would further and faster than if their skeletons were made of bone now let's look at another body part that sharks are famous for their teeth have you ever lost a baby tooth and then an adult tooth grew in well sharks loser teeth all the time throughout their entire lives and they just keep growing new ones how can they do that you and I just have one row of teeth in her mouth but sharks have a lot of rows of teeth on the top and the bottom so when a shark loses a tooth another tooth that's right behind it can just move on up to take its place because they always have new teeth to replace the old ones some sharks can lose thousands of teeth during their lives alright the next cool thing about sharks their skin if you could rub the skin of a shark you'd find that it would feel smooth here and your hand in one direction but if you rub your hand the other way it would feel rough like a cat's talk that's because a shark skin is covered in top body skills that actually look a little like tiny teeth these little scales are stacked on top of each other like tiles on a route this helps sharks swim through the water quickly and quietly so those are some of the things that all sharks have but there are over 400 50 types of sharks in the world and that means a lot of differences to take a look at this one it's called a whale shark and it's the biggest shark there is in fact is the largest fish in the whole world whale sharks can grow to be as long as a school was but even though they're so big they eat tiny plants and super small animals called plankton that flow in the water but not all sharks are as big as the whale shark some can also be tiny meet the dwarf lanternshark it's so small it could fit in my hand this sharp lives in the deep ocean where there's very little light so it has big eyes to help see in the dark plus it has a really neat feature yes special organs on its belly fins and tail that actually glow scientists think this might help the lanternshark Lauren pray for it to eat plus when it's in shallow water where there's more light these blowing lights can help it blend in to avoid predators finally I'd like you to meet a very special shark say hello to the Greenland shark this big shark spends most of its time swimming in very cold water hanging out near the sea floor looking for an easy snack but scientists have recently discovered something amazing about these animals Greenland sharks can live to be up to 400 years old of all the animals in the world with backbones known as vertebrates Greenland sharks live the longest at least that we know what scientists are still discovering new kinds of sharks all the time so who knows what kind of super sharks are still out there waiting to be found what's your favorite animal do you want to learn more about it just ask a grown-up to help you and leave a comment below or send us an email to kids at the size of dot-com we're excited to hear from you oh and we're also really excited because we're making some changes to the fort so stay tuned and we'll share a few surprises with you in the upcoming weeks thanks mostly excited here before