counter-gradient variation in respiratory performance of coral reef fishes at elevated temperaturescounter-gradient呼吸的变化珊瑚礁鱼类在升高的温度下的性能.pdfVIP

Counter-Gradient Variation in Respiratory Performance of Coral Reef Fishes at Elevated Temperatures 1,2 1,2 ¨ 3 Naomi M. Gardiner *, Philip L. Munday , Goran E. Nilsson 1 School of Marine and Tropical Biology, James Cook University, Townsville, Australia, 2 Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia, 3 Physiology Programme, Department of Molecular Biosciences, University of Oslo, Oslo, Norway Abstract The response of species to global warming depends on how different populations are affected by increasing temperature throughout the species’ geographic range. Local adaptation to thermal gradients could cause populations in different parts of the range to respond differently. In aquatic systems, keeping pace with increased oxygen demand is the key parameter affecting species’ response to higher temperatures. Therefore, respiratory performance is expected to vary between populations at different latitudes because they experience different thermal environments. We tested for geographical variation in respiratory performance of tropical marine fishes by comparing thermal effects on resting and maximum rates of oxygen uptake for six species of coral reef fish at two locations on the Great Barrier Reef (GBR), Australia. The two locations, Heron Island and Lizard Island, are separated by approximately 1200 km along a latitudinal gradient. We found strong counter-gradient variation in aerobic scope between locations in four species from two families (Pomacentridae and Apogonidae). High-latitude populations (Heron Island, southern GBR) performed significantly better than low-latitude populations (Lizard Island, northern GBR) at tem