The effects of temperature on oxygen consumption of eggs and hatchlings of the nile crocodile ( Crocodylus niloticus)

Abstract

1. 1. The oxygen uptake ( V ̇ O 2 ) of eggs and hatchlings of the Nile crocodile was measured at ambient temperatures ( T a ) of 25, 32 and 37°C. 2. 2. At a T a of 32°C, V ̇ O 2 was found to be stable during the last month of incubation. It, howe increased with 15% after hatching. 3. 3. Embryos and hatchlings increased their V ̇ O 2, following exposure to increasing temperatures. At T a , between 25 and 32°C Q 10 were 1.83 and 2.3 for the eggs and hatchlings, respectively. The Q 10 decreased to 1.27 for the eggs but that of hatchlings increased to 2.59 at T a between 32 and 37°C. 4. 4. Exposure of eggs to pure oxygen at T a of 37°C was accompanied by an increase in metabolism ( V ̇ O 2) to a level similar to that of hatchlings kept in air. 5. 5. It is postulated that a combination of high temperature and environmental oxygen may reduce the incubation time of the crocodile eggs.