Ammonia
Ammonia is very toxic and dissolves quickly in body fluids. Thus it must be kept in low concentration in the body. To maintain its low concentration, body requires, large volume of water also to eliminate it in urine as it is produces. This is possible in a hypotonic environment. Therefore, ammonia kept as the excretory product of the animals inhabiting hypotonic environment about 500ml water is needed to excrete 1g of ammonia nitrogen.
Urea
In restricted supply of water, ammonia changes to less toxic substance such as urea. Urea requires only 50ml of water for its 1g of nitrogen removal. Here excretory nitrogen is metabolically converted into urea by urea cycle in the animals inhabiting environment with restricted supply of water e.g., terrestrial mammals.
Uric acid
In animals inhabiting environment with acute shortage of water supply require an excretory product which can be excreted with minimum mount of water. Only 1ml water is required to eliminate 1g of nitrogen in the form of uric acid.
Ammonia is very toxic and dissolves quickly in body fluids. Thus it must be kept in low concentration in the body. To maintain its low concentration, body requires, large volume of water also to eliminate it in urine as it is produces. This is possible in a hypotonic environment. Therefore, ammonia kept as the excretory product of the animals inhabiting hypotonic environment about 500ml water is needed to excrete 1g of ammonia nitrogen.
Urea
In restricted supply of water, ammonia changes to less toxic substance such as urea. Urea requires only 50ml of water for its 1g of nitrogen removal. Here excretory nitrogen is metabolically converted into urea by urea cycle in the animals inhabiting environment with restricted supply of water e.g., terrestrial mammals.
Uric acid
In animals inhabiting environment with acute shortage of water supply require an excretory product which can be excreted with minimum mount of water. Only 1ml water is required to eliminate 1g of nitrogen in the form of uric acid.