Question

where is the rate of breathing in aquatic organism is much faster than the Terrestrial organisms

Answer 1

that's why rate of breathing is faster in aquatic animals than Terrestrial organisms

Answer 2

The water bodies have comparatively low amount of oxygen as compared to Oxygen concentration in the air. So, the aquatic organisms have to breathe faster in order to get more amount of Oxygen while breathing.
Hence, the rate of breathing in aquatic organisms is comparatively faster as compared to that in terrestrial organisms.