Temperature regulation in ectotherms

This chapter explores temperature regulation in ectotherms. Almost all invertebrates, all amphibians, most fish, and most reptiles are ectotherms. Ectotherms influence their body temperatures by behavioural thermoregulation. The simplest form of behavioural thermoregulation is thermal selection according to the preferred body temperatures of aquatic animals. Meanwhile, terrestrial ectotherms adjust their rate of heat uptake and heat loss by shuttle behaviour. The chapter then looks at albedo, melanism, and thermal hysteresis. Some animals cope with cold conditions by entering a resting phase called diapause or hibernation. The chapter also considers the implications of temperature change for tissue functioning of ectotherms. According to the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis, the capacity for oxygen uptake and transport is the major determinant of thermal tolerance of aquatic ectotherms.