Rev. 01/01/2020
Metabolic pathways to excretion differ in animals of different habitat of animals. Nitrogenous waste products, usually in the form of ammonia, result from metabolic pathways that involve proteins and amino acids.
Since ammonia is toxic, terrestrial animals, including arthropods and vertebrates, generally bind the –NH3 group into either urea or uric acid, which is accumulated prior to excretion. Such organisms are termed uricotelic.
Nematodes are aquatic organisms, inhabiting marine and fresh waters and the water films of soil environments. Like most aquatic organisms, they continually excrete ammonia into the environment as it is produced, thus avoiding the toxic storage problem. Such organisms are termed ammonotelic (Perry and Wright, 1998). The excretion of waste nitrogenous products into the soil environment may be a significant contribution to nitrogen availability to plants (Ferris, et al., 1998;Chen and Ferris, 1999).
Chen, J and H. Ferris. 1999. The effects of nematode grazing on nitrogen mineralization during fungal decomposition of organic matter. Soil Biol. And Biochem. 31:1265-1279.
Ferris, H., R.C. Venette, H.R. van der Meulen and S.S. Lau. 1998. Nitrogen mineralization by bacterial-feeding nematodes: verification and measurement. Plant and Soil 203:159-171.
Perry, R.N. and D.J. Wright. 1998. The Physiology and Biochemistry of Free-living and Plant-parasitic Nematodes. CABI Publishing, Wallingford, UK.