How are fish able to breathe underwater?

Answer 1

Well,Fish Can Breathe Under water because, First of all fish are not mammals,and fish are put in their own group because fish have gills that give them the ability to breathe underwater. Mammals(Humans) have lungs that allow us to breath oxygen.Humans can be underwater for a short period of time because people hold their breath for short period of time.

But the answer is gills because instead of breathing oxygen, gills are made for breathing underwater,just like fish!If you catch a fish,when you take it out of the water it starts to flap,and then if you keep it out long enough,The fish will stop breathing because fish are not made for breathing air,Just like a fish gills.

I hoped this Helped!

-[-[-[-[Lipeod

Answer 2

Humans can't breath under water because they evolved to be land creatures and therefore were not born with gills, fins, etc. If the first human had been born under water and then given birth to a child that child might have been born with slightly better features for living under water than its parents, but because humans supposedly evolved from apes, we are land animals and are born with land animal features.

Our lungs take oxygen, and our body is incapable of extracting oxygen from water. Therefore, to get that oxygen we need, we have to stay above the water or supply it artificially (eg., Scuba tank).

If we were to live underwater, the only thing to eat would be other raw fish, because we couldn't walk on land. (Some people are Vegans!) Also, it was the way we were created. I really don't see why we can't live on land and in water, but, we will just have to deal with it. :(

Answer 3

Generally speaking, fish have gills which are specialized to bring blood close to the surface in thin membranes that allow oxygen to pass through to the blood. Human lungs can't pull oxygen out of water, we need oxygen in air. Now, the mechanics of why we can't pull oxygen out of water might be chemical (myoglobin attracts oxygen in human blood, perhaps fish have a better system). Besides air vs. water, we also need oxygen at certain concentrations, if you go too high in elevation or altitude, you can't breathe because there isn't enough oxygen to support what your using.
Breathing and drinking are two different things. To drink is to digest a liquid and use its benefits. Breathing is taking in oxygen in some way and using it for bodily functions within your cells.
We cannot breathe under water like a fish because our lungs require oxygen. Fish have gills and their gills allow oxygen to be extracted from water. We don't have gills hense we cannot breathe underwater. - Jossie 12 years old :)

Answer 4

They are different from above water mammals we have lungs they have gills.