Ammonotelic, ureotelic and uricotelic animals are defined as follows.
Ammonotelic animals – Specieswhich excrete ammonia in their waste are called ammonotelic animals. Ammonia is highly poisonous and water-soluble and is produced by quick diffusion of water.
Examples: Ammonotelic is the majority of marine animals namely cnidarians, echinoderms, fishes, protozoans, larvae/tadpoles of amphibians, crustaceans, poriferans and platyhelminths.
Ureotelic animals – Species which excrete waste in the form of waste are called ureotelic animals. Urea is less harmful than ammonia and requires less water.
Examples: Organisms include few bony fishes, adult amphibians, fish, cartilaginous fish and mammals including human.