What and why are there different types of nitrogenous waste? (4)

Type of nitrogenous waste in animals is linked with the evolutionary history of the animal and habitat aquatic animals: ammonia (NH3) = toxic but water soluble Birds, Reptiles, insects: uric acid (C5H4N4O3) = needs more energy but is non toxic and less concentrated Mammals + amphibians: urea (CH4N2O) = non toxic and can be stored at higher concs