NSF Award
0116442
A grant has been awarded to Dr. Paul Sotherland at Kalamazoo College to purchase a Columbus Instruments Micro-Oxymax Multiple Sensor O2/CO2 20 Chamber System and three Precision Low-temperature Incubators. The Columbus Micro-Oxymax system is the best multiple-chamber system available for sequentially measuring metabolic rates (i.e. rates of oxygen consumption and carbon dioxide production) of a wide variety of small organisms, maintained at various gas concentrations , via closed-system respirometry. The Precision incubators are dependable, standard-refrigerator sized, incubators that typically are used to maintain small organisms at a constant temperature (set point + 0.5 degree C). The equipment will be used to attain the following two goals: (1) to investigate the metabolic responses of turtle embryos to hypoxia at different stages of development and, thereby, (a) elucidate general patterns of physiological response to hypoxia by three turtle species that typically experience different degrees of hypoxia in the nest during incubation, and (b) determine whether hatchery nests of leatherback turtles, one of the three species studied, would produce relatively more hatchlings if they were ventilated with humidified air toward the end of incubation; and (2) to train undergraduate students in the use of the purchased equipment while carrying out the proposed research and other research projects that involve the measurement of metabolism.<br/>The PI and undergraduate student collaborators will incubate eggs of snapping turtles (Chelydra serpentina), olive ridley turtles (Lepidochelys olivacea), and leatherback turtles (Dermochelys coriacea) (half-buried in sand in plastic boxes ventilated with air or gas maintained at levels of nest normoxia and held in two of the incubators) and assess their responses to different levels of acute hypoxia by measuring their metabolic rates (while holding them in small chambers at the incubation temperature in the third incubator). Egg and hatchling size, along with blood parameters (hematocrit and hemoglobin concentration) of hatchlings, will also be measured.<br/>This research will expand our understanding of the developmental physiology of oviparous amniotes while enriching the education of many undergraduate students. Because an embyro's environment and its genome both affect developmental trajectories followed by the embryo and phenotype of the hatchling, research on the effects of hypoxia on embryonic development will provide new insights into the ecological and evolutionary consequences of hatchling phenotypes. Experiments required to complete this research will be performed through a collaboration between the PI and Kalamazoo College undergraduate students working in the lab to measure metabolism and in the field to collect eggs at Playa Grande, Costa Rica, and at Kalamazoo College's Lillian Anderson Arboretum. These projects, and others using the equipment, will therefore have positive impacts on the life-long learning of many students.
