Why do fish have gills?

Fish need gills for the respiration under the water. Gills are the respiratory organs in the fish. As human beings and other mammals need lungs to extract oxygen from the air, gills are used by the fish to extract oxygen from the water.

Fish breathe with their gills, which are tissues made up of feathery organs full of blood vessels, known as gill filaments. It provides a large surface area for the exchange of gases.

Fishes breathe in oxygen-rich water via their mouths and pump it over their gills. When water moves over the gill filaments, the blood present in the capillary network takes up the dissolved oxygen.

Now, the circulatory system supplies oxygen to the whole body, while taking up carbon dioxide that is breathed out through the gills from the body. 


Simply Easy Learning

Updated on: 09-May-2023


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