Larval thermal conditioning does not improve post-settlement thermal tolerance in the dominant reef-building coral, Montipora capitata
Larval thermal conditioning does not improve post-settlement thermal tolerance in the dominant reef-building coral, Montipora capitata
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DOI：
10.1007/s00338-022-02234-x
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发表时间：
2022-02-18
期刊：
影响因子：
3.5
通讯作者：
Matsuda, Shayle B.
中科院分区：
文献类型：
--
作者：
Alexander, Gyasi;Hancock, Joshua R.;Matsuda, Shayle B.
气候变化引起的海洋变暖重塑了珊瑚礁生态系统，珊瑚白化事件继续导致全球珊瑚大规模死亡。当热应激事件在关键的繁殖和补充期间持续发生时，这些热异常也会对珊瑚礁的持久性和恢复产生负面影响。因此，全球珊瑚礁的补充（早期生命阶段的定居和存活）持续下降，损害了大规模白化和死亡事件后珊瑚礁系统的恢复，从而导致这些珊瑚礁生态功能的丧失。主动恢复框架内的一项缓解策略包括在苗圃中繁殖珊瑚（即成年碎片、幼虫或幼体），然后将其直接种植到珊瑚礁底栖动物中。恢复计划可以极大地受益于有性繁殖珊瑚繁殖体的使用，经过优化后，可以增加外植种群的可扩展性和遗传多样性。幼体饲养过程中的热调节有可能成为一种具有成本效益且可扩展的策略，以提高后续生命阶段的生存和应激耐受力。在这里，我们测试了幼虫阶段热调节的潜力，以对头彩玫瑰卵的应激耐受性产生积极的潜在影响。我们将幼虫暴露在凉爽（24.5 摄氏度）、环境（27.2 摄氏度）和温暖（28.9 摄氏度）条件下四天，在此期间我们跟踪幼虫的存活情况。在幼虫阶段进行热调节后，我们测量了沉降成功率，然后将卵暴露在 47 天的高温胁迫（+ 2 摄氏度）下并测量了存活率。我们发现幼虫热调节并不能为幼虫在高温下提供生存益处。此外，幼虫暴露在环境温度之外会损害其生存，这表明虽然在卵中没有观察到积极的潜在影响，但优化热条件对于最大限度地提高珊瑚幼虫的生存和定居非常重要。
Climate change-induced ocean warming has reshaped reef ecosystems as coral bleaching events continue to lead to mass coral die-offs globally. These thermal anomalies also negatively affect reef persistence and recovery when heat stress events continue to occur during critical reproduction and recruitment periods. As a result, recruitment (settlement and survival of early life stages) continues to decline on reefs globally, compromising the recovery of reef systems following mass bleaching and mortality events, which has led to the loss of ecological function on these reefs. One mitigation strategy within the active restoration framework includes propagated corals (i.e., adult fragments, larvae, or juveniles) produced in nurseries that are then directly out planted to the reef benthos. Restoration programs can greatly benefit from use of sexually derived coral propagules, which when optimized, increase the scalability and genetic diversity of outplanted stock. Thermal conditioning during larval rearing has the potential to be a cost-effective and scalable strategy to enhance the survival and stress tolerance of subsequent life stages. Here, we tested the potential for thermal conditioning during the larval stage to induce positive latent effects on the stress tolerance of Montipora capitata spat. We exposed larvae to cool (24.5 degrees C), ambient (27.2 degrees C), and warm (28.9 degrees C) conditions for four days and during this period we tracked larval survival. Following thermal conditioning during the larval stage, we measured settlement success and then exposed spat to a 47-day high temperature stress (+ 2 degrees C) and measured survival. We found that larval thermal conditioning did not provide survival benefits to spat under elevated temperature. Furthermore, larval exposure to temperatures outside of an ambient regime compromised survival, suggesting that although positive latent effects were not observed here in spat, optimizing thermal conditions is important for maximizing survival and settlement of coral larvae.