Unlike humans have noses and mouths conjointly working for their respiration system, fish do not possess them for their respiration system. They have gills which are like pores on their fins and body portion. They also need oxygen which gills provide them with. They respire through gills because they inhale oxygenated water and gills take out all the oxygen from them and allow the body tissues to flow oxygen to the different body-parts. This process is although little complicated yet easily done through gills in fish. The efficiency of the flow of oxygen through gills depends on the blood and water flowing in opposite direction. This can be increased to 70 per cent as a fish can extract oxygen from the gills up to 70 per cent. Another reason to have gills in the fish is that all the waste products are released through the pores of gills. Hence, fish need gills for respiration system.
Why do Fish Respire through Gills?
