Record Details

Bartholomew, George A;Vleck, David
The relation of oxygen consumption to body size and to heating and cooling in the Galapagos marine iguana, Amblyrhynchus cristatus
Journal of Comparative Physiology B
Journal Article
Amblyrhynchus cristatus
In Amblyrhynchus cristatus oxygen consumption increases with mass to the 0.78 power at 25°C and with mass to the 0.70 power at 35°C. The two exponents are not significantly different, nor do they differ significantly from the figures for lizards as a group. At any given body temperature between 18 and 36° C in Amblyrhynchus of all body sizes oxygen consumption is usually higher during cooling than during heating. In a 2500 g lizard cooling under natural conditions, endogenous heat production equals about 29% of heat loss. During heating under natural conditions it equals about 5% of heat gain. We conclude that metabolic heat production is relatively unimportant in accelerating temperature increase in Amblyrhynchus during basking, and that although it can significantly decrease the rate of cooling it is probably an incidental by-product of attempts to employ behavioral thermoregulation.