1. An animal living in water uses oxygen dissolved in water.
2. The solubility of oxygen in water is much lower. So the amount of oxygen available is much lesser than air, hence the rate of breathing is faster in aquatic animals.
3. Fish take in water through the mouth and release it over the gills.
4. Gills are the site for uptake of dissolved oxygen into the blood by diffusion.
2. The solubility of oxygen in water is much lower. So the amount of oxygen available is much lesser than air, hence the rate of breathing is faster in aquatic animals.
3. Fish take in water through the mouth and release it over the gills.
4. Gills are the site for uptake of dissolved oxygen into the blood by diffusion.
