Osinga Ronald, Derksen-Hooijberg Marlous, Wijgerde Tim, Verreth Johan A J
Wageningen University, Marine Animal Ecology, PO Box 338, Wageningen 6700 AH, The Netherlands
Radboud University Nijmegen, Aquatic Ecology & Environmental Biology, Heyendaalseweg 135, Nijmegen 6525 AJ, The Netherlands.
J Exp Biol. 2017 Jun 15;220(Pt 12):2236-2242. doi: 10.1242/jeb.140509. Epub 2017 Apr 21.
Rates of dark respiration and net photosynthesis were measured for six replicate clonal fragments of the stony coral (Linnaeus 1767), which were incubated under 12 different combinations of dissolved oxygen (20%, 100% and 150% saturation), dissolved carbon dioxide (9.5 and 19.1 µmol l) and water flow (1-1.6 versus 4-13 cm s) in a repeated measures design. Dark respiration was enhanced by increased flow and increased oxygen saturation in an interactive way, which relates to improved oxygen influx into the coral tissue. Oxygen saturation did not influence net photosynthesis: neither hypoxia nor hyperoxia affected net photosynthesis, irrespective of flow and pH, which suggests that hyperoxia does not induce high rates of photorespiration in this coral. Flow and pH had a synergistic effect on net photosynthesis: at high flow, a decrease in pH stimulated net photosynthesis by 14%. These results indicate that for this individual of , increased uptake of carbon dioxide rather than increased efflux of oxygen explains the beneficial effect of water flow on photosynthesis. Rates of net photosynthesis measured in this study are among the highest ever recorded for scleractinian corals and confirm a strong scope for growth.
对石珊瑚（林奈，1767年）的六个重复克隆片段进行了暗呼吸速率和净光合作用速率的测量，这些片段在溶解氧（20%、100%和150%饱和度）、溶解二氧化碳（9.5和19.1微摩尔/升）和水流（1 - 1.6与4 - 13厘米/秒）的12种不同组合下进行培养，采用重复测量设计。暗呼吸以交互方式因水流增加和氧饱和度增加而增强，这与珊瑚组织中氧流入的改善有关。氧饱和度不影响净光合作用：无论水流和pH值如何，低氧和高氧均不影响净光合作用，这表明高氧不会在该珊瑚中诱导高光合呼吸速率。水流和pH值对净光合作用有协同作用：在高水流下，pH值降低可使净光合作用提高14%。这些结果表明，对于这种石珊瑚个体，二氧化碳吸收增加而非氧流出增加解释了水流对光合作用的有益影响。本研究中测得的净光合作用速率是有记录以来造礁石珊瑚中最高的，证实了其强大的生长潜力。
