The effects of temperature and dehydration on renal function in the Nile Crocodile, Crocodylus niloticus Laurenti.

Abstract

Change of ambient temperature between 32ºC and 15ºC reduced urine production of Crocodylus niloticus from 1.15 to 0.27 cm3 kg-1 h-1, the glomerular filtration rate from 5.21 to 2.21 cm3 kg-1 h-1, and the effective renal blood flow from 24.21 to 4.60 cm3 kg-1 h-1. The tubular secretion of phenolsulfonthalein was markedly depressed by temperature, 20.2% of an injected amount being excreted after 6h at 32ºC, but only 2.4% after 6h at 15ºC. Mild dehydration (2.7% loss in body mass over 24 h) reduced urine production from 1.15 to 0.17 cm3 kg-1 h-1 and the glomerular filtration rate from 5.21 to 1.09 cm3 kg-1 h-1. Mild dehydration had a small but statistically insignificant effect on phenolsulfonthalein secretion.


Transactions of the Zimbabwe Scientific AssociationVolume 72 1998, pp. 18-22