Browsing by Author "Warner,Mark E."
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Item Microelectrode characterization of coral daytime interior pH and carbonate chemistry(Nature Publishing Group, 4/4/16) Cai,Wei-Jun; Ma,Yuening; Hopkinson,Brian M.; Grottoli,Andrea G.; Warner,Mark E.; Ding,Qian; Hu,Xinping; Yuan,Xiangchen; Schoepf,Verena; Xu,Hui; Han,Chenhua; Melman,Todd F.; Hoadley,Kenneth D.; Pettay,D. Tye; Matsui,Yohei; Baumann,Justin H.; Levas,Stephen; Ying,Ye; Wang,Yongchen; Wei-Jun Cai, Yuening Ma, Brian M. Hopkinson, Andre�a G. Grottoli, Mark E. Warner, Qian Ding, Xinping Hu, Xiangchen Yuan, Verena Schoepf, Hui Xu, Chenhua Han, Todd F. Melman, Kenneth D. Hoadley, D. Tye Pettay, Yohei Matsui, Justin H. Baumann, Stephen Levas, Ye Ying, Yongchen Wang; Hoadley,Kenneth D.;Warner, Mark E;Cai, Wei-JunReliably predicting how coral calcification may respond to ocean acidification and warming depends on our understanding of coral calcification mechanisms. However, the concentration and speciation of dissolved inorganic carbon (DIC) inside corals remain unclear, as only pH has been measured while a necessary second parameter to constrain carbonate chemistry has been missing. Here we report the first carbonate ion concentration ([CO32-]) measurements together with pH inside corals during the light period. We observe sharp increases in [CO32-] and pH from the gastric cavity to the calcifying fluid, confirming the existence of a proton (H+) pumping mechanism. We also show that corals can achieve a high aragonite saturation state (Omega(arag)) in the calcifying fluid by elevating pH while at the same time keeping [DIC] low. Such a mechanism may require less H+-pumping and energy for upregulating pH compared with the high [DIC] scenario and thus may allow corals to be more resistant to climate change related stressors.Item Partitioning of Respiration in an Animal-Algal Symbiosis: Implications for Different Aerobic Capacity between Symbiodinium spp.(Frontiers Media SA, 4/18/16) Hawkins,Thomas D.; Hagemeyer,Julia C. G.; Hoadley,Kenneth D.; Marsh,Adam G.; Warner,Mark E.; Thomas D. Hawkins, Julia C.G. Hagemeyer, Kenneth D. Hoadley, Adam G. Marshand Mark E.Warner; Warner, Mark ECnidarian-dinoflagellate symbioses are ecologically important and the subject of much investigation. However, our understanding of critical aspects of symbiosis physiology, such as the partitioning of total respiration between the host and symbiont, remains incomplete. Specifically, we know little about how the relationship between host and symbiont respiration varies between different holobionts (host-symbiont combinations). We applied molecular and biochemical techniques to investigate aerobic respiratory capacity in naturally symbiotic Exaiptasia pallida sea anemones, alongside animals infected with either homologous ITS2-type A4 Symbiodinium or a heterologous isolate of Symbiodinium minutum (ITS2-type B1). In naturally symbiotic anemones, host, symbiont, and total holobiont mitochondrial citrate synthase (CS) enzyme activity, but not host mitochondrial copy number, were reliable predictors of holobiont respiration. There was a positive association between symbiont density and host CS specific activity (mg protein(-1)), and a negative correlation between host- and symbiont CS specific activities. Notably, partitioning of total CS activity between host and symbiont in this natural E. pallida population was significantly different to the host/symbiont biomass ratio. In re-infected anemones, we found significant between-holobiont differences in the CS specific activity of the algal symbionts. Furthermore, the relationship between the partitioning of total CS activity and the host/symbiont biomass ratio differed between holobionts. These data have broad implications for our understanding of cnidarian-algal symbiosis. Specifically, the long-held assumption of equivalency between symbiont/host biomass and respiration ratios can result in significant overestimation of symbiont respiration and potentially erroneous conclusions regarding the percentage of carbon translocated to the host. The interspecific variability in symbiont aerobic capacity provides further evidence for distinct physiological differences that should be accounted for when studying diverse host-symbiont combinations.Item Spectral Reflectance of Palauan Reef-Building Coral with Different Symbionts in Response to Elevated Temperature(MDPI Ag, 2/23/16) Russell,Brandon J.; Dierssen,Heidi M.; LaJeunesse,Todd C.; Hoadley,Kenneth D.; Warner,Mark E.; Kemp,Dustin W.; Bateman,Timothy G.; Brandon J. Russell, Heidi M. Dierssen, Todd C. LaJeunesse, Kenneth D. Hoadley, Mark E. Warner, Dustin W. Kemp and Timothy G. Bateman; Hoadley, Kenneth D;Warner, Mark ESpectral reflectance patterns of corals are driven largely by the pigments of photosynthetic symbionts within the host cnidarian. The warm inshore bays and cooler offshore reefs of Palau share a variety of coral species with differing endosymbiotic dinoflagellates (genus: Symbiodinium), with the thermally tolerant Symbiodinium trenchii (S. trenchii) (= type D1a or D1-4) predominating under the elevated temperature regimes inshore, and primarily Clade C types in the cooler reefs offshore. Spectral reflectance of two species of stony coral, Cyphastrea serailia (C. serailia) and Pachyseris rugosa (P. rugosa), from both inshore and offshore locations shared multiple features both between sites and to similar global data from other studies. No clear reflectance features were evident which might serve as markers of thermally tolerant S. trenchii symbionts compared to the same species of coral with different symbionts. Reflectance from C. serailia colonies from inshore had a fluorescence peak at approximately 500 nm which was absent from offshore animals. Integrated reflectance across visible wavelengths had an inverse correlation to symbiont cell density and could be used as a relative indicator of the symbiont abundance for each type of coral. As hypothesized, coral colonies from offshore with Clade C symbionts showed a greater response to experimental heating, manifested as decreased symbiont density and increased reflectance or "bleaching" than their inshore counterparts with S. trenchii. Although no unique spectral features were found to distinguish species of symbiont, spectral differences related to the abundance of symbionts could prove useful in field and remote sensing studies.