HOW DO FISH BREATHE  UNDER THE WATER?

LIKE ALL ANIMALS, FISH NEED OXYGEN TO LIVE. SO THEY HAVE GOT THE GILLS, TWO SPREADS AT THEIR HEAD'S SIDES ALLOWING THEM TO TAKE OXYGEN FROM THE WATER. THE CLOSED GILLS FISH SWALLOWS WATER FROM ITS MOUTH. WATER CROSSES THE LAMELLA INTO THE GILLS WHERE THE OXYGEN IS SEPARATED FROM WATER AND ABSORBED BY THE BLOOD VASES TO GO OUT FROM THE OPEN GILLS. THESE ORGANS OPEN AND CLOSE RHYTHMICALLY AND IN THE SAME WAY THE TERRESTRIAL HUMAN BEINGS ALTERNATE THE RESPIRATORY MOUVEMENTS.

Marco