How Can Fish Breathe in Water?

How can fish breathe in water? Fish breathe with gills, which are inside the fish’s head on each side of its throat. Some fish have as few as two gills in each chamber and some have as many as five gills. Gill pouches, through which the water flows, separate the gills from one another.

Each gill has an artery flowing through it. The artery branches off into many small blood vessels. The gills are made of a thin material that allows the fish’s blood to come close to the surface of the gills.

Water contains large amounts of oxygen. When a fish breathes, it takes a mouthful of water, and then closes its mouth. This forces the water past the gills.

The oxygen in the water is absorbed through the thin surfaces of the gills, and into the fish’s blood. The water then leaves the fish’s body through narrow gill slits on each side of its head. Now we know how can fish breathe in water.

What gas do fish breathe out? Land-living organisms, as humans, breathe oxygen from the air; fish breathe oxygen from the water. Carbon dioxide is produced by animals and humans. It’s coming out in the air from our lungs and into the water as the water flow through the fish’s gills.

Why can’t fish breathe in air? Though some fish can breathe on land taking oxygen from air. Most of the fish, when taken out of water, suffocate and die. This is because gill arches of fish collapse, when taken out of water, leaving the blood vessels no longer exposed to oxygen in air.

Content for this question contributed by Tony Mayer, resident of Carroll, Carroll County, Iowa, USA