Question

Why is rate of breathing in aquatic organisms is much faster than in terristial organisms

Answer 1

Aquatic animals take in the oxygen dissolved in water. The amount of dissolved oxygen in water is fairly low compared to the amount of oxygen in the air. Therefore, rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

Answer 2

as the amount of oxygen is much lesser in water than in  the terrestial atmosphere . Thus, they breathe faster in order to provide sufficient oxygen to the body.