Fertilization by coral-dwelling fish promotes coral growth but can exacerbate bleaching response
Fertilization by coral-dwelling fish promotes coral growth but can exacerbate bleaching response
复制标题
DOI：
10.1016/j.jtbi.2022.111087
复制
发表时间：
2022-03-16
影响因子：
2
通讯作者：
V. Moeller, Holly
中科院分区：
文献类型：
--
作者：
Detmer, Raine;Cunning, Ross;V. Moeller, Holly
许多珊瑚与各种各样的珊瑚鱼类和其他动物群形成密切的联系。随着世界各地的珊瑚礁越来越受到大规模漂白事件的威胁，了解这些生物相互作用如何影响珊瑚对漂白的敏感性是很重要的。我们使用动态能量收支模型来探索珊瑚鱼排泄的氮如何影响宿主珊瑚的生理表现。在我们的模型中，鱼类的存在影响了coralSymbiodiniaceae共生的功能，通过改变氮的可用性，这些影响的大小和迹象取决于环境条件。虽然我们的模型预测，鱼类来源的氮可以促进珊瑚的生长，鱼类的存在和珊瑚的光氧化应激的耐受性之间的关系是非线性的。鱼的排泄物支持密集的共生种群，提供保护，从入射光通过自我遮光。然而，这些共生体也将更多的光合产物用于自己的生长，而不是与珊瑚宿主分享，使珊瑚全生物面临更高的碳限制和漂白风险。共生体遮荫增加的好处和减少碳共享的成本之间的平衡取决于环境条件。因此，虽然在某些情况下，鱼类的存在增加了珊瑚对光胁迫的耐受力，但鱼类也可能加剧白化，减缓或阻止随后的恢复。我们讨论了我们的模型和实证研究的结果预测的鱼的潜在有害影响之间的对比可能涉及到关键的模型假设，值得进一步调查。总的来说，这项研究为珊瑚相关动物群如何影响其宿主珊瑚的生物能量学的未来工作提供了基础，这反过来又影响了这些珊瑚如何应对漂白诱导的压力。(c)2022作者由爱思唯尔有限公司出版。这是一篇在CC BY-NC-ND许可证下的开放获取文章（http：//creativecommons.org/licenses/by-nc-nd/4.0/）。
Many corals form close associations with a diverse assortment of coral-dwelling fishes and other fauna. As coral reefs around the world are increasingly threatened by mass bleaching events, it is important to understand how these biotic interactions influence corals' susceptibility to bleaching. We used dynamic energy budget modeling to explore how nitrogen excreted by coral-dwelling fish affects the physiological performance of host corals. In our model, fish presence influenced the functioning of the coralSymbiodiniaceae symbiosis by altering nitrogen availability, and the magnitude and sign of these effects depended on environmental conditions. Although our model predicted that fish-derived nitrogen can promote coral growth, the relationship between fish presence and coral tolerance of photo-oxidative stress was non-linear. Fish excretions supported denser symbiont populations that provided protection from incident light through self-shading. However, these symbionts also used more of their photosynthetic products for their own growth, rather than sharing with the coral host, putting the coral holobiont at a higher risk of becoming carbon-limited and bleaching. The balance between the benefits of increased symbiont shading and costs of reduced carbon sharing depended on environmental conditions. Thus, while there were some scenarios under which fish presence increased corals' tolerance of light stress, fish could also exacerbate bleaching and slow or prevent subsequent recovery. We discuss how the contrast between the potentially harmful effects of fish predicted by our model and results of empirical studies may relate to key model assumptions that warrant further investigation. Overall, this study provides a foundation for future work on how coral-associated fauna influence the bioenergetics of their host corals, which in turn has implications for how these corals respond to bleaching-inducing stressors. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).