Question

Q.22 Why an aquarium fish open and close their mouths at regular intervals?

Answer 1

aquarium fish opens its mouth regularly to take in water along with dissolved oxygen and closes the mouth regularly to push this water to gills where dissolved oxygen is separated from it and supplied to body. The gills of fish are covered by bony lid. The fish takes in water by closing the lid on its gills and opening its mouth, now as the fish closes its mouth the water is supplied to the gills. The gills contain filaments that have lamellae which increases the surface area of the gills to extract more oxygen from water. In this way fish open and closes the mouth alternately for respiration. Plz mark as brainliest