The main difference between the aquatic environment and the ground-air one?

There is an aquatic, land-air, soil and organismic environment. The main difference between the aquatic and ground-air environment is that in the aquatic environment, organisms are surrounded by water, and in the ground-air environment – by a mixture of gases. These are primarily nitrogen, oxygen and carbon dioxide. Also, this includes a number of other gases. The aquatic environment also contains oxygen and other gases, but in a dissolved form. Fish, for example, absorb oxygen through their gills. Terrestrial animals have bronchi and lungs for this in the structure of the body.