P1.209 Wednesday, Jan. 4 High Latitude Oceans in a High CO2 World: Comparative Analysis of the Metabolic Response of Antarctic Notothenioids to a Multi-Stressor Scenario ENZOR, Laura A.*; PLACE, Sean P.; University of South Carolina; University of South Carolina email@example.com
For Notothenioid fishes of the Southern Ocean, evolution in extremely stable, cold waters has resulted in several physiological adaptations that likely come with a high metabolic cost. For instance, production of antifreeze glycoproteins for freeze avoidance, or the constant expression of the inducible heat shock protein, Hsp70, in response to reduced protein folding efficiency, necessitate the reallocation of precious energy expenditures away from growth and reproduction. Additionally, these fish have adapted to their cold environment by increasing mitochondrial density, utilizing lipids as a primary energy source, thereby eliminating the need for a swim bladder, as well as lowering enzyme activation temperatures. Thus, in the face of increasing global climate change, the metabolic cost of maintaining cellular homeostasis in these stenothermal fish may be significantly impacted. While the effects of thermal stress on teleost metabolic rates have been well documented, there is little to no data on the effects of potential synergistic stressors. We have begun a comparative study to identify changes in cellular energetics that may result from predicted changes to ocean environments. We have used intermittent aquatic respirometry of whole animals to compare the basal metabolic response of several Nothenioid species to the combined effects of increasing water temperatures and decreasing ocean pH levels. In addition, we measured the oxygen utilization of isolated hepatocytes in the presence and absence of inhibitors in an effort to identify changes in energy allocation under this multi-stressor scenario.