Endothermy in marine reptiles: An approach examining body size and metabolic rate

Abstract

Endothermy is the regulation of body temperature using metabolic heat, while ectothermy is the regulation of body temperature using external heat sources. Reptiles are generally ectothermic animals, but some large marine reptiles are known to be highly endothermic and to maintain their body temperatures at above environmental temperatures. An animal’s body temperature is determined by the balance of thermal energy entering and leaving the body and is closely related to body size and metabolic rate. In this paper, I focus on sea turtles as endothermic marine reptiles and explain how they maintain body temperatures elevated above water temperatures, focusing on body size and metabolic heat. In addition, I also show differences in observed resting metabolic rates and body temperatures between two genetically isolated populations of loggerhead turtles and discuss the ecological implications of this difference.