Question: How can fish breath underwater but we can't ?

Kate Salmon answered on 17 Mar 2014:

Hi @bluebubble36- Fish are adapted to breathing underwater because they have gills which are kind of like our lungs. There are lots of blood vessels in a fish’s gills which means that when the water comes in contact with the gill, the oxygen in the water dissolves into the gills and the fish can breathe. If you ever watch a fish underwater, you can see it moving it’s gills like it is breathing. This works the same for human’s lungs but instead of water carrying the oxygen, it is air. If we tried to breathe water into our lungs instead of air, we would drown and likewise, if a fish tried to breathe air instead of water, it would drown too.