Squeaks and I are adopting a pet goldfish!
He lives in a fish tank, and he’s a great swimmer!
In fact, this little guy’s whole body is really suited to life in the water.
He has great fins to help him swim, and eyes that can stay open in the water.
These special body parts help him to live in his underwater home, so we call them adaptations.
There’s one adaptation that’s really important for our new fish friend to survive in a fish
tank or pond.
He needs to be able to breathe underwater.
People can’t breathe underwater because there’s no air.
We have to hold our breath, or use special equipment like scuba gear to get air.
But our goldfish isn’t holding his breath, and he didn’t bring scuba gear!
实际上 他不是在空气中呼吸 而是在水中呼吸的
Instead of breathing air, he actually breathes water.
人类 鱼 还有其他一切动物 都为了一个理由呼吸
Humans, fish, and all kinds of other animals have to breathe for the same reason: we all
need something called oxygen.
Even though air might not seem like it’s made of anything, it’s actually made up of lots
of tiny things called molecules that are way too small for you to see.
Oxygen is one of the ingredients in air, and it’s really important: it helps your body
分解食物 活动肌肉 甚至动动脑子
You need oxygen to break down your food, move your muscles, and even just to think with
氧气存在于空气中 而你需要让它进入体内 并且充满整个身体
There’s oxygen in air, but you need it to get into and all around your whole body!
So, you have special organs called lungs to help get that oxygen.
当你吸气的时候 你能感受到你的肺因充满空气而膨胀 像气球一样
When you breathe in, you can feel your lungs expand full of air, just like a balloon.
Once they’re full of air, your lungs pull the oxygen that you need out of the air before
you breathe out.
That oxygen goes into your blood and travels all throughout your body.
我们周围到处都是空气 所以只要你能呼吸 就可以获得氧气
There’s air all around us, so as long as you we breathe, you can get oxygen.
Land animals can have all different shapes and sizes of lungs, but animals that live
underwater, like fish, need oxygen, too!
Fish don’t have lungs, and there isn’t any air around them.
Animals like our goldfish need to use another way to get their oxygen.
And guess what?
Water is full of oxygen, just like the air is!
So fish can get their oxygen straight from the water they live in.
They just need an adaptation to get the oxygen out of the water.
Instead of lungs, most underwater creatures have another special body part that allows
them to pull oxygen straight out of the water, called their gills.
Gills look like little slits on either side of a fish’s face.
A fish’s gills work a lot like our lungs.
When a fish pulls in water through its mouth, the water goes back out through its gills.
As the water runs through the gills, it goes right past the fish’s blood.
The oxygen in the water flows into the fish’s blood, and now the fish can use the oxygen
all over its body!
所以 鱼是用腮在水里呼吸 而不是用肺在空气中呼吸的
The fish is basically breathing water with gills, instead of air with lungs.
Other types of animals besides fish use gills, too.
螃蟹 龙虾 蜗牛甚至一些小虫 都是用腮呼吸的
Crabs, lobsters, snails, and even some bugs use gills to breathe!
So, even though we both have very different ways of getting it, our goldfish needs oxygen
just like I do.
Isn’t that right, little fish?
What do you think we should name our new fish?
Ask a grown-up to help you leave a comment below, or you can send us an email at firstname.lastname@example.org
Thanks, and we’ll see you next time here at the Fort!