Aquatic animals generally are ammonotelic in nature whereas terrestrial forms are not. Comment.
The removal of the substance ammonia from the body requires plenty of water due to its highly toxic nature. This does not create problems with the aquatic animals as there is plenty of water available which has made them ammoniotelic, i.e. the animals which excrete ammonia. However, in the case of animals living in terrestrial habitat, the water availability is limited, and hence they are not ammoniotelic and show ureotelism.