Can saltwater fish also live in freshwater or vice versa?

Answer

Dear Oscar,

There are very few fish that can do this (eg eel and salmon). The problem lies in the amount of salt in their bodies and in the fish.

You can research this yourself so that you understand it better. Have a piece of potato when your mom or dad makes fries. Weigh this piece of potato. Then put it in salt water and weigh it again after half an hour. Do the same with a piece of potato that you put in plain water. You will see that the potato becomes lighter in the salt water. This is because the water in the potato gets out. In the ordinary water, the potato becomes lighter because water enters the potato.

When a freshwater fish swims in salt water, the same thing happens as a potato: the fish loses its water and dies. The saltwater fish that swims in the common water swells because the water enters the fish.

The fish should have as much salt in its body as there is in the water.

Sincerely

stephan boulez

LEctor World Orientation, Primary Education Education