Aerobic metabolism of the lizardVaranus exanthematicus: Effects of activity, temperature, and size |
| |
Authors: | Stephen C Wood Kjell Johansen Mogens L Glass and G M O Maloiy |
| |
Institution: | (1) Department of Zoophysiology, University of Aarhus, DK-8000 Aarhus C, Denmark;(2) Present address: Department of Physiology, The University of New Mexico, School of Medicine, 87131 Albuquerque, New Mexico, USA;(3) Present address: Department of Animal Physiology, University of Nairobi, Nairobi, Kenya |
| |
Abstract: | Summary Oxygen consumption
was measured at rest and during spontaneous activity at body temperatures of 25 and 35°C in 14 fasting Savanna monitor lizards,Varanus exanthematicus ranging in weight from 172 to 7500 g. The allometric relationship between metabolic rate at 25°C and body weight (W) is given by:
(ml O2 STPD·g–1·hr–1)=0.88W
–0.43 (Fig. 2). Although statistical comparisons are equivocal, this intraspecific size dependence exceeds that reported for interspecific comparisons among reptiles and other vertebrate groups (Fig 3). A reproducible diurnal pattern of activity was observed in undisturbed animals with minimum values of
between 2400 and 0800 h (Fig. 1). Spontaneous activity and
generally reached peak values between 1200 and 2000 hrs. The average ratio of active aerobic metabolic rate (AMR) to minimum (standard) aerobic metabolic rate (SMR) was 8.2. This voluntary AMR/SMR inVaranus exceeds the AMR/SMR for most reptiles stimulated to exhaustion. The high aerobic capacity is consistent with other evidence for efficient exchange and transport of respiratory gases inV. exanthematicus; e.g., low or absent intracardiac shunt flow resulting in high arterial saturation and low ventilation
and perfusion
requirements. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|