Classify the animals based on the type of nitrogenous waste

Classification of animals based upon the types of main nitrogenous wastes:

a. Ammonotelic animals:

The main nitrogenous waste is ammonia, e.g., certain protozoans, polycheate annelids, crustacean arthropods, molluscs (Aplysia, Sepia and Octopus), fresh water teleost fishes, tadpoles of am­phibia and crocodiles.

b. Ureotelic animals:

Main nitrogenous waste is Urea, e.g., elasmobranch fishes, amphibians and mammals.

c. Uricotelic animals:

Main waste is uric acid, e.g., insects, some gastro­pods, lizards, snakes and birds.