How to fish breath, because if we tried to breathe under the water we would gulp down water?

Question: How to fish breath, because if we tried to breathe under the water we would gulp down water?
- Keywords:
  breathe,
  fish,
  underwater
Asked by zblondie to Carol on 2 Jul 2012.
- Carol White answered on 2 Jul 2012:
  
  Fish have gills instead of lungs! So water passes through these tiny flaps and the fish get their oxygen this way!
  
  In each gill, there are lots of rows of tiny specialised cells called “epithelium”. Deoxygenated blood in the fish is goest from the heart to the epithelium via arteries. When the gills force seawater over the rows of epithelium , dissolved oxygen in the seawater is taken up by tiny blood vessels and veins, while the carbon dioxide is exchanged – just like the aveoli in our lungs!

Question: How to fish breath, because if we tried to breathe under the water we would gulp down water?