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