Developmental plasticity and adaptive capacity of the cardiorespiratory system of fishes and amphibians

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Our research programs use aquatic animals to address pressing questions in evolutionary ecology and developmental biology. This research is multi-disciplinary and shares a long-term objective to understand the complex interactions between animals and their environments. Understanding the development and adaptation of the cardiorespiratory system is a central component of our research. The limits of the cardiorespiratory system determine an animal’s capacity to perform aerobic activities, and if the cardiorespiratory system is unable to meet baseline demands for oxygen it will result in death. Cardiac output represents the capacity of the heart to deliver oxygenated blood to tissues, and is an important physiological trait that shapes the relationship between environments and fitness. Direct measurements of blood flow are the gold-standard for determining cardiac output, but in the past have been limited by the need for invasive and time-consuming surgery to insert cardiac probes. Recently, technological advances have enabled blood flow to be measured using an external Doppler probe. The present grant thus requests funding to purchase a Doppler Flow Velocity System, which will enable real-time, minimally invasive measurements of cardiac output in aquatic animals, and would be the first Doppler Flow Velocity System in Canada dedicated to the study of fishes and amphibians. Over the next 5 years, the equipment requested in this RTI will be used to conduct four major projects that will train 8 graduate students, 10 undergraduate students and 2 postdoctoral fellows. The first project will focus on understanding the thermal ecology of fishes as it relates to the resiliency of populations to climate change and the design of conservation breeding programs. The second project will use zebrafish as a model organism to study key genes that are identified as candidates to mediate heart development and cardiac output in the first project. The third project will focus on understanding developmental changes in cardiac output associated with metamorphosis in a frog and how physiological constraints affect mortality at this vulnerable life stage. The fourth project will examine how disruptive selection associated with alternative reproductive tactics and foraging ecology has shaped variation in cardiac output. Together the four projects will advance our research programs by addressing fundamental questions in biology, while providing practical knowledge that will be critical for managing and safeguarding valuable Canadian fishes and amphibians.