Ammonia excretion

Ammonia excretion

Animal can also be divided on the basis of their excretory material which is related to their habitat and body metabolism. There is no general pathway for nitrogen excretion in plants. The major excretory material in animal is nitrogen, in animals it is not directly excreted but through formation of various compounds, on the basis of excretion animals can be divided in to three types (table below)

01             Ammonotelic animals excrete amino nitrogen as ammonia

       (most aquatic species, such as the bony fishes)

02             Ureotelic animals excrete amino nitrogen in the form of urea.

       (most terrestrial animals)

03             Urecotelic animals excrete amino nitrogen as uric acid.

       (birds and reptiles)

 

Classification based on ammonia excretion

Waste         Advantage           Disadvantages       Habitat              Excreted by

Ammonia    Produced with      Toxic conc.             Water                 Marine and

                   little energy          solution. Requires                              fresh water

                                                a lot of water for                                invertebrates,

                                                excretion.                                            bony fish,

                                                                                                           amphibian

Urea            Less toxic than     Requires little         Land sea            Adult amphibians,

                   ammonia               more energy to                                  mammals

                   requires less          produce it

                   water for

                   excretion

Uric acid     Very little water   Requires consi        Land                 Reptiles, birds,

is required for     durable energy                                 insects, land gastro

excretion             to produce it                                    pods

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