Meeting Abstract
Heart rate is an informative physiological trait that is measured in many studies because it can be an index of the workload of the cardiovascular system as it transports gasses, nutrients, and hormones throughout the body. Detecting changes in heart rate can allow researchers to study the effects of variable conditions during embryonic development. Measuring the heart rates of developing embryos, however, is logistically more challenging than measurements in adult organisms. The Buddy® system is a digital egg monitor that detects heart rates without affecting embryogenesis. The Buddy® utilizes infrared light to noninvasively measure embryonic heart rates, and though originally designed for bird embryos, this device has also been useful in detecting heart rates of non-avian reptile embryos. Currently, it has primarily been used on species that lay relatively large eggs, such as turtles and iguanas. In this study, we evaluated the effectiveness of the Buddy® system at measuring heart rates of embryos in a lizard species that produces very small eggs (~0.1 g), the brown anole (Anolis sagrei). Eggs from captive anoles were incubated under fluctuating incubation temperatures, mimicking a natural, daily temperature regime. We utilized the Buddy® system to examine how heart rates change both throughout a daily temperature cycle and throughout embryonic development. Preliminary results suggest heart rates are positively correlated with daily temperature fluctuations, but not age of the embryo. While the Buddy® was effective at measuring heart rates of A. sagrei, we outline several limitations to its utility for measuring heart rates of small eggs. Despite these limitations, we present the first baseline measures of anole heart rates and recommend the Buddy® system as a tool to further expand the utility of anoles as model systems in evolution, ecology, and physiology.
