why the rate of breathing is faster in aquatic animals than land animals ?
The oxygen source i.e., water is about 800 times denser than air. It contains less O2 as compared to air. Since the content of O2 in water is low, aquatic animals breathe faster to get as much oxygen as possible, resulting in a faster rate of breathing. Therefore, aquatic animals breathe faster than terrestrial animals and also show different adaptations for better gaseous exchange.