The relative contribution of dinoflagellate photosynthesis and stored lipids to the survivorship of symbiotic larvae of the reef-building corals
The relative contribution of dinoflagellate photosynthesis and stored lipids to the survivorship of symbiotic larvae of the reef-building corals
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DOI：
10.1007/s00227-010-1401-0
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发表时间：
2010-06-01
期刊：
影响因子：
2.4
通讯作者：
Hoegh-Guldberg, Ove
中科院分区：
文献类型：
--
作者：
Harii, Saki;Yamamoto, Masanobu;Hoegh-Guldberg, Ove
幼虫的远距离传播为造礁珊瑚的种群之间提供了重要的联系，是珊瑚生物学的一个重要组成部分。一些珊瑚浮游虫具有共生甲藻（Symbiodinium spp.）除了提供蛋内的脂质外，可能还提供能量。然而，我们对共生体对浮游虫能量代谢和存活的影响的了解仍然有限。本研究探讨共生甲藻光合作用和储存的脂质含量的珊瑚Pocillopora damicornis和Montipora digitata的发展阶段的生存的相对作用。我们发现，在黑暗条件下（即没有光合作用活性），红角拟步行虫和M. digitata分别在释放/产卵后31和22天。结果表明，黄角拟步行虫和黄腹拟步行虫的脂肪含量均高于其它两种拟步行虫。当与光照条件相比时，在黑暗条件下，扁平指状体显示出以更高的速率显著降低。当转换成能量当量时，脂耗提供的可利用能量分别占天牛幼虫代谢的41.9%和84.7%，占天牛的38.4%和90.1%。digitata（到第21天）。这一发现表明，并不是所有的能量需求的幼虫满足脂质：能源也来自这些幼虫内的共生甲藻的光合作用活动，特别是在光照条件下。此外，三个主要的脂质类（蜡酯，甘油三酯和磷脂）的量下降，在整个实验中的两个物种的浮浪，与蜡酯含量下降更迅速地在黑暗条件下比在光照条件下。这两个物种的浮游植物从蜡酯中获得大量的能量，共生甲藻使幼虫能够以较低的速率使用它们的商店，这表明共生甲藻有潜力在光照条件下延长幼虫的寿命。
The long-distance dispersal of larvae provides important linkages between populations of reef-building corals and is a critical part of coral biology. Some coral planulae have symbiotic dinoflagellates (Symbiodinium spp.) that probably provide energy in addition to the lipids provisioned within the egg. However, our understanding of the influence of symbionts on the energy metabolism and survivorship of planulae remains limited. This study examines the relative roles of symbiotic dinoflagellate photosynthesis and stored lipid content in the survivorship of the developing stages of the corals Pocillopora damicornis and Montipora digitata. We found that survivorship decreased under dark conditions (i.e. no photosynthetic activity) for P. damicornis and M. digitata at 31 and 22 days after release/spawning, respectively. The lipid content of P. damicornis and M. digitata planulae showed a significant decrease, at a higher rate, under dark conditions, when compared with light conditions. When converted to energy equivalents, the available energy provided by the depletion of lipids could account for 41.9 and 84.7% of larval metabolism for P. damicornis (by day 31) and 38.4 and 90.1% for M. digitata (by day 21) under light and dark conditions, respectively. This finding indicates that not all energy requirements of the larvae are met by lipids: energy is also sourced from the photosynthetic activities of the symbiotic dinoflagellates within these larvae, especially under light conditions. In addition, the amounts of three main lipid classes (wax esters, triglycerides, and phospholipids) decreased throughout the experiment in the planulae of both species, with the wax ester content decreasing more rapidly under dark conditions than under light conditions. The observations that the planulae of both species derive considerable amounts of energy from wax esters, and that symbiotic dinoflagellates enable larvae to use their stores at lower rates, suggested that symbiotic dinoflagellates have the potential to extend larval life under light conditions.