Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA.
J Exp Biol. 2011 Aug 15;214(Pt 16):2783-90. doi: 10.1242/jeb.055343.
This study describes the effects of temperature on the respiration of brooded larvae of scleractinian corals, and evaluates the implications of these effects relative to seawater temperature when peak larval release occurs. Respiration rates of larvae from Pocillopora damicornis, Seriatopora hystrix and Stylophora pistillata were quantified in darkness as oxygen uptake during 1-3 h exposures to five temperatures between 26.4 and 29.6°C. To assess the biological significance of these experiments, the temperature of the seawater into which larvae of P. damicornis and S. hystrix were released was measured for 32-34 months over 5 years between 2003 and 2008. Mean respiration varied from 0.029 to 0.116 nmol O(2) larva(-1) min(-1), and was related parabolically to temperature with a positive threshold at 28.0°C. The temperature coefficients (Q(10)) for the ascending portion of these relationships (Q(10)=15-76) indicate that the temperature dependency is stronger than can be explained by kinetics alone, and probably reflects behavioral and developmental effects. Larval release occurred year-round in synchrony with the lunar periodicity when seawater temperature ranged from 21.8 to 30.7°C, and more than half of the sampled larvae were released at 27.5-28.9°C. The coincidence on the temperature scale of peak larval release with the thermal threshold for respiration suggests that high metabolic rates have selective value for pelagic coral larvae. The large and rapid effects of temperature on larval respiration have implications for studies of the effects of climate change on coral reproduction, particularly when seawater temperature exceeds ∼28°C, when our results predict that larval respiration will be greatly reduced.
本研究描述了温度对有腔肠幼虫呼吸的影响，并评估了在峰值幼虫释放时海水温度下这些影响的意义。在黑暗中，定量测量了来自鹿角珊瑚、蜂巢珊瑚和石珊瑚的幼虫的呼吸速率，这些幼虫在 1-3 小时内暴露于 26.4 至 29.6°C 的 5 个温度下，通过氧摄取来测量。为了评估这些实验的生物学意义，在 2003 年至 2008 年的 5 年期间，测量了 32-34 个月内鹿角珊瑚和蜂巢珊瑚幼虫释放到海水中的温度。平均呼吸速率从 0.029 到 0.116 nmol O(2)幼虫(-1) min(-1)不等，与温度呈抛物线关系，正阈值为 28.0°C。这些关系上升部分的温度系数（Q(10)）（Q(10)=15-76）表明，温度依赖性比单独的动力学解释更强，可能反映了行为和发育效应。幼虫释放全年与月球周期性同步发生，当海水温度在 21.8 至 30.7°C 之间时，超过一半的采样幼虫在 27.5-28.9°C 释放。在温度范围内，峰值幼虫释放与呼吸的热阈值相吻合，这表明高代谢率对浮游珊瑚幼虫具有选择价值。温度对幼虫呼吸的巨大和快速影响对气候变化对珊瑚繁殖影响的研究具有意义，特别是当海水温度超过约 28°C 时，根据我们的结果预测，幼虫呼吸将大大减少。
