The effects of temperature and dehydration on renal function in the Nile Crocodile, <i>Crocodylus niloticus</i> 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