How Can Some Fish Live in Water That Is Colder than Freezing?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. How can some fish live in water that is colder than freezing?

The Big Idea

Some fish can live in water colder than freezing because they make their own antifreeze! The antifreeze is made of special proteins in their blood and body fluids. It keeps tiny ice crystals from growing, so the fish keep swimming happily.

Salty Sea

Step one: seawater is salty. Because it is salty, seawater freezes at about 28.8 degrees Fahrenheit, colder than fresh water. That is the temperature of the water around Antarctica.

Fish Blood

Step two: a fish problem. A fish's body fluids would freeze at a slightly warmer temperature than the seawater. That could be big trouble, if the fish did nothing about it.

Antifreeze Proteins

Step three: make antifreeze. Antarctic fish make special antifreeze proteins. The proteins stick to tiny ice crystals and stop them from growing, so the fish's body fluids keep flowing.

A Closer Look

Let's take a closer look! The sea near Antarctica is freezing cold. Salt keeps the seawater from freezing until it gets very cold. The fish's proteins stop little ice crystals from growing. So the fish swim along without any trouble.

Quick Facts

Quick facts! Scientists discovered fish antifreeze in the 1960s. It was a surprise, because scientists first wondered how fish could live there at all. Other animals, like some insects, make antifreeze, too. Ask a grown-up to help with any freezer science.

Think Like a Scientist

Now, think like a scientist! With a grown-up, stir salt into a cup of water and put it in the freezer next to a cup of plain water. Check them after an hour or two. Which one freezes later? Salt lowers the freezing point! Share what you discover with a grown-up.

Outro

Antarctic fish stay safe in freezing water with natural antifreeze. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!