OXYGEN-UPTAKE BY KOMODO-DRAGON (VARANUS-KOMODOENSIS) EGGS - THE ENERGETICS OF PROLONGED DEVELOPMENT IN A REPTILE

Oxygen consumption was measured during incubation in the eggs of the Komodo dragon (Varanus komodoensis), a reptile that exhibits prolonged embryonic development. Oxygen consumption of eggs (mean mass 175 g) showed a sigmoidal pattern over the course of an incubation period, averaging 235.6 d at 29 degrees C. The rate Of oxygen consumption during the plateau prior to hatching averaged 151.1 mL/d. The incubation time was 210% greater and the peak oxygen consumption 53.2% less than predicted by existing allometric equations Analysis of incubation time data indicates that the Komodo dragon is not unique in having prolonged incubation times relative to those of previously studied reptiles that do not undergo diapause. The cost of development in dragons averaged 329.4 kJ (1.88 kJ/g egg mass), which is significantly higher than predicted. These results are consistent with those predicted from models of developmental energetics based on avian species.