Nitrogenous Excretion in Crocodiles
نویسندگان
چکیده
Animals in general are known to fall into three main groups, ammonoteles, ureoteles or uricoteles according to whether ammonia, urea or uric acid is the main nitrogenous excretory metabolite in the urine. Among reptiles, Lacertilia and Ophidia are known to be uricoteles, chelonian tortoises were found to be ureo-uricoteles (Khalil & Haggag, 1955). Crocodilia—represented by alligators, crocodiles and gavials—is the least-studied reptilian order in respect of its nitrogenous excretion. The data available in the literature are those of Lewis (1918), Hopping (1923) and Coulson, Hernandez & Brazda (1950) on the analysis of urinary excreta of Alligator mississippiensis. These authors claim that alligators are ammonoteles. The only work on crocodiles, as the present authors can ascertain, was done by Moore as early as 1851 on Crocodylus vulgaris (Winterstein, 1924), but the urine sample he examined was not fresh, since it was taken from an animal 36 hr. after death and was analysed 30 days later, by which time it had a very bad smell. Moore stated that the urine contained a white precipitate of ammonium urate and that urea was absent. The present work was undertaken on C. niloticus to extend knowledge on nitrogenous excretion in Crocodilia.
منابع مشابه
Adaptations to a Terrestrial Existence by the Robber Crab, Birgus Latro L. Iii. Nitrogenous Excretion
Nitrogenous excretion by the terrestrial anomuran crab Birgus latro L. was examined. The main excretory product was uric acid, representing 79-5 % of total excretory nitrogen. It was eliminated as white faeces separate from undigested food material and made up 82-6% of excretory faecal nitrogen. The faeces were the principal route of nitrogenous excretion, accounting for 96-2% of total excretio...
متن کاملDogmas and controversies in the handling of nitrogenous wastes: excretion of nitrogenous wastes in human subjects.
Two major nitrogenous waste products, urea and ammonium (NH(4)(+)), are produced in humans when proteins are oxidized, and in this manuscript their excretions are examined from two perspectives. First, the specific physiology of each nitrogenous waste is reviewed and the current dogmas summarized. Second, their excretions are considered in the context of integrative physiology, i.e. the need to...
متن کاملDogmas and controversies in the handling of nitrogenous wastes: the effect of feeding and fasting on the excretion of ammonia, urea and other nitrogenous waste products in rainbow trout.
Ammonia and urea are the primary forms of nitrogen excretion in teleost fish. There exists, however, a discrepancy between the sum of ammonia plus urea nitrogen and total nitrogen, indicating that 'unknown' nitrogen end products may play an important role in nitrogen metabolism. The current study analysed a wide range of nitrogen end products in both fed and fasted juvenile rainbow trout. Ammon...
متن کاملUrinary excretion of nitrogenous and non-nitrogenous compounds in the chronic ethanol-fed rat.
1. The metabolic consequences of chronic ethanol feeding was investigated by assay of urinary metabolites. Male Wistar rats were fed a liquid diet containing 35% of total energy as ethanol or isovolumetric, isocaloric and isonitrogenous amounts of the same diet in which ethanol was substituted by isocaloric glucose (controls). 2. At 6 weeks the entire skeletal muscle mass was reduced by approxi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005