Question

What advantage a terrestrial animal has over an aquatic animal with regard to obtaining oxygen for respiration?

Answer 1

A terrestrial animal is surrounded by an oxygen-rich atmosphere from which it can easily absorb oxygen. In contrast, an aquatic animal must rely on the oxygen dissolved in water to carry out respiration. Because the amount of oxygen dissolved in water is significantly lower than the amount of oxygen in the air, aquatic animals must breathe at a much faster rate.