What does a salmon breathe?

Salmon, like all fish, breathe oxygen. They don't breathe air like we do, but instead, they extract oxygen dissolved in the water through their gills.

Here's how it works:

1. Water enters the mouth: Salmon take water into their mouths and pass it over their gills.

2. Gills extract oxygen: The gills are made up of thin filaments covered in tiny blood vessels. As water flows over the gills, oxygen diffuses from the water into the blood.

3. Carbon dioxide released: At the same time, carbon dioxide from the blood diffuses into the water and is expelled.

4. Water exits the gills: The water, now depleted of oxygen and enriched with carbon dioxide, exits the gills through openings called gill slits.

This process allows salmon to extract the oxygen they need to survive underwater.