| 摘要: |
| 选择三亚鹿回头近岸海域常见的鹿角杯形珊瑚（Pocillopora damicornis）幼虫为研究对象，采用室内连续培养的方法，探究了升温（29 ℃和31 ℃）与硝酸盐加富（0、5、20 μmol/dm3）对鹿角杯形珊瑚幼虫共生体的生理影响。结果表明：升温和硝酸盐加富对鹿角杯形珊瑚幼虫存活率与共生虫黄藻叶绿素荧光指数（Fv/Fm）无显著影响，但对幼虫附着率的影响表现为明显的交互作用。升温条件下，各处理珊瑚幼虫附着率均显著下降，且硝酸盐加富加剧了升温对珊瑚幼虫附着率的负面影响。再者，升温对幼虫呼吸速率的影响与硝酸盐的浓度有关， 5 μmol/dm3硝酸盐处理抵消了升温对幼虫呼吸的促进作用；与此同时， 5 μmol/dm3硝酸盐处理提高了幼虫的净光合作用而且光合呼吸速率比（PG/RD）大于2，表明此时珊瑚幼虫共生体系光合作用固定的有机碳为净累积。综上，适量的硝酸盐加富可以缓解升温对珊瑚幼虫代谢的负面影响，但高浓度硝酸盐加富则会不利于鹿角杯形珊瑚幼虫的附着及种群的本地补充。 |
| 关键词: 海洋生物学 鹿角杯形珊瑚幼虫 升温 硝酸盐 附着 呼吸速率 |
| DOI：10.3969/J.ISSN.2095-4972.2020.02.003 |
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| 基金项目:国家自然科学基金资助项目（41876192，41676150）；国家重点研发计划资助项目（2017YFC0506301）；广东省省级科技计划资助项目（2017B0303014052） |
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| Physiological effects of elevated temperature and nitrate enrichment on the larvae of scleractinian coral Pocillopora damicornis |
| ZHANG Fang,SUN You-fang,YU Xiao-lei,JIANG Lei,HUANG Hui |
| (CAS Key Laboratory of Tropical Marine Bioresources and Ecology， South China Sea Institute of Oceanology， Chinese Academy of Sciences， Guangzhou 510301， China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences， Beijing 100049， China;CAS Key Laboratory of Tropical Marine Bioresources and Ecology， South China Sea Institute of Oceanology， Chinese Academy of Sciences， Guangzhou 510301， China; Tropical Marine Biological Research Station in Hainan， Chinese Academy of Sciences， Sanya 572000， China) |
| Abstract: |
| This study tested the physiological effects of elevated temperature （29℃， 31℃） and nitrate （NO3-） enrichment （0， 5， 20 μmol/dm3） on the brooded larvea of Pocillopora damicornis from Luhuitou fringing reef， Sanya， China. Results showed that warming and nitrate （NO3-） enrichment did not significantly influence larval survival rate and maximum quantum yield （Fv/Fm）. However， it showed a significant interaction between elevated temperature and nitrate （NO3-） enrichment on larval settlement. Nitrate enrichment acted synergistically with elevated temperature and it reduced the settlement rate of P. damicornis larvae. Furthermore， the effects of elevated temperature on dark respiration of coral larvae were also dependent on the nitrate concentration， where a 5 μmol/dm3 nitrate enrichment inhibited the stimulation of respiration with increased temperature. At the same time， 5 μmol/dm3 nitrate treatment enhanced the net photosynthesis with the ratio of photosynthesis to respiration （PG/RD） greater than 2， indicating a net accumulation of photosynthetically fixed organic carbon under 5 μmol/dm3 nitrate. Our results suggest that modest nitrate enrichment can mitigate the negative effects of warming on the metabolism of larvae in the stony coral P. damicornis， while high nitrate enrichment would exacerbate the larval settlement and population recruitment． |
| Key words: marine biology Pocillopora damicornis larvae elevated temperature nitrate settlement respiration rate |
