Natural Variations in Nitrogen Excretion of Amphibians from Different Habitats
1968
Schmid, William D.
Analyses of ammonia and urea concentrations of anuran amphibians from different habitats showed that aquatic species had significantly lower levels of plasma urea than more terrestrial species. There was also a greater tendency for urea to be partitioned into the urine of aquatic species. Ammonia content of urine was higher in the more aquatic forms, but varied greatly within species depending upon the state of hydration of the specimen. High levels of urinary ammonia were used as a basis of critical evaluation of the ecology of B. hemiophrys. The adaptive values of natural variations in patterns of nitrogen are discussed relative to interspecific differences in ecology and water balance.
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