Record Details

White, Fred N
Temperature and the Galapagos marine iguana - insights into reptilian thermoregulation
Comparative Biochemistry and Physiology. Part A: Physiology
Journal Article
Amblyrhynchus cristatus
1. Marine iguanas regulate core temperature under increasing thermal loads. Regulation correlates with behavior. 2. Elevated basking (EB) is initiated within a narrow range of body temperatures (Tb). The principal exteroreceptor for adjusting body attitude appears to be the eyes. 3. Panting can be induced when EB is prevented but occurs at a higher Tb than was encountered under field conditions. Panting is an effective mechanism for stabilizing Tb. 4. EB minimizes radiant heating but cannot account for stability of Tb under successively warmer conditions. Creation of a ventrally located heat sink and associated cardiovascular changes allow construction of a model which deficits the animal as a regulated “heat shunt”. 5. Night cooling rate is attenuated by aggregating. 6. Immature animals regulate Tb by vertical shuttling in the thermal gradients of crevices. 7. Major thermoregulatory interactants are discussed.