title: Light respiratory processes and gross photosynthesis in two scleractinian corals.
abstract: The light dependency of respiratory activity of two scleractinian corals was examined using O2 microsensors and CO2 exchange measurements. Light respiration increased strongly but asymptotically with elevated irradiance in both species. Light respiration in Pocillopora damicornis was higher than in Pavona decussata under low irradiance, indicating species-specific differences in light-dependent metabolic processes. Overall, the coral P. decussata exhibited higher CO2 uptake rates than P. damicornis over the experimental irradiance range. P. decussata also harboured twice as many algal symbionts and higher total protein biomass compared to P. damicornis, possibly resulting in self-shading of the symbionts and/or changes in host tissue specific light distribution. Differences in light respiration and CO2 availability could be due to host-specific characteristics that modulate the symbiont microenvironment, its photosynthesis, and hence the overall performance of the coral holobiont.
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia.
authors.forename: Verena
authors.initials: V
authors.lastname: Schrameyer
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wangpraseurt
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia; Centre for Marine Bio-Innovation and Sydney Institute of Marine Science, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Ross
authors.initials: R
authors.lastname: Hill
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia; Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark; Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Michael
authors.initials: M
authors.lastname: Kühl
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia.
authors.forename: Anthony W D
authors.initials: AW
authors.lastname: Larkum
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Ralph
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism* / Q000502:physiology / Q000528:radiation effects*; D001692:Biological Transport / Q000528:radiation effects; D002245:Carbon Dioxide / Q000378:metabolism; D008027:Light; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000528:radiation effects*; D012119:Respiration / Q000528:radiation effects*; D013559:Symbiosis / Q000528:radiation effects
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen