Grant: Discovery Grants Program - Individual

As a complex trait, animal thermal physiology involves the co-evolution of thermal sensation along with biochemical mechanisms of thermal tolerance. Therefore, ectothermic animals with different body temperatures should show functional differences in how they sense temperature. Understanding how organisms regulate their body temperature and use volitional thermal choices is important since it illustrates their potential to respond to changes in the environment. My laboratory takes an integrative approach to these questions, focusing primarily on vertebrate ectotherms (e.g., fish, reptiles) and studying conserved as well as their unique mechanisms that allow them to modify and regulate their internal body temperature. I employ the term "visualizing thermoregulation" as a focus for the next 5 years to demonstrate how we use behavioural physiology in addition to non-invasive imaging technologies in our research. The ultimate goal of my research program is to understand the thermoregulatory strategies that animals use to cope with environmental changes, and ultimately, to understand the how the body's `thermostat' has evolved. The objectives of the next five years of my proposed research will examine the 3 primary "drivers" (internal / central drivers, peripheral / sensory drivers, and the evolutionary and ecological drivers). The first objective will examine the control of Tb in animals by examining the physiological relevance of altered thermoregulatory states. This will involve experiments primarily in fish models we have developed (rivulus, zebrafish, round gobies), and the use of pharmacological blockade to decipher proposed pathways that play a role in behavioural thermoregulation. We will also focus on how the mangrove rivulus have adapted to their life on land, how they have adopted a novel thermoregulatory strategy hitherto unavailable to aquatic counterparts. The second objective will examine the peripheral mechanisms related to thermoregulation. We will examine mechanisms of warm and cold thermosensation and establish their roles in thermoregulatory behaviours through a comparative analysis of animals with different thermoregulatory preferences. We will continue our research into the trade-offs between water balance and thermoregulation in reptiles, by examining scaleless phenotypes of bearded dragons and the impact this has on thermal behaviour and water balance. The third objective will adapt our knowledge from the lab into field applications, especially in endangered or threatened species, so as to translate and apply our expertise to pertinent and urgent biological questions. We plan to incorporate non-invasive approaches to study peripheral vasomotion in the field in lizards and tortoises as part of a study examining thermoregulation in the field. This will involve the use of novel logging technology (NIRS) developed in diving seals to examine blood oxygenation changes in peripheral structures.