Higuchi Tomihiko, Agostini Sylvain, Casareto Beatriz Estela, Suzuki Yoshimi, Yuyama Ikuko
Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan.
Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan.
Sci Rep. 2015 Dec 18;5:18467. doi: 10.1038/srep18467.
The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones.
日本珊瑚的分布涵盖了广泛的纬度范围，包括热带到温带地区。然而，温带地区的珊瑚群落仅包含一小部分物种。在决定珊瑚分布的参数中，温度起着重要作用。我们在孵化实验中测试了三种鹿角珊瑚属珊瑚物种对冷胁迫的恢复力。三种物种中分布最靠北的霜鹿角珊瑚在13°C时白化，但温度升高后恢复。另外两种物种，风信子鹿角珊瑚和比霜鹿角珊瑚分布更靠南的独立鹿角珊瑚，在13°C白化后迅速死亡。冷白化对珊瑚的生理影响包括光合作用、呼吸作用和钙化速率降低，这与高温胁迫导致的白化所观察到的生理影响相似。与热白化形成对比的是，未观察到抗氧化酶活性增加，这表明活性氧在冷胁迫下的白化过程中作用较小。这些结果证实了恢复力对冷胁迫在决定珊瑚物种分布和北界方面的重要性，因为在温带地区，导致珊瑚白化和高死亡率的寒冷事件经常发生。
