If the ocean is full of salt, why don't fish get thirsty?

The answer:

Fish don't drink the ocean water because their body fluids are saltier than the ocean. This means that if they drank ocean water, they would lose water from their bodies instead of gaining it.

This is because fish have a special organ called a gill that allows them to extract oxygen from the water without taking in too much salt. Gills are made up of thin membranes that allow water to pass through them, but they block out the salt.

In addition, fish have a special type of kidney that helps them to remove excess salt from their bodies. This means that they can stay hydrated even in the saltiest of waters.

So, the next time you see a fish swimming in the ocean, don't worry about it getting thirsty. It's perfectly adapted to its environment and doesn't need to drink any water.