Kindsvater Holly K, Juan-Jordá Maria-José, Dulvy Nicholas K, Horswill Cat, Matthiopoulos Jason, Mangel Marc
Department of Fish and Wildlife Conservation Virginia Polytechnic Institute and State University Blacksburg Virginia USA.
Earth to Ocean Research Group, Department of Biological Sciences Simon Fraser University Burnaby British Columbia Canada.
Evol Appl. 2024 Feb 7;17(2):e13646. doi: 10.1111/eva.13646. eCollection 2024 Feb.
Understanding how growth and reproduction will adapt to changing environmental conditions is a fundamental question in evolutionary ecology, but predicting the responses of specific taxa is challenging. Analyses of the physiological effects of climate change upon life history evolution rarely consider alternative hypothesized mechanisms, such as size-dependent foraging and the risk of predation, simultaneously shaping optimal growth patterns. To test for interactions between these mechanisms, we embedded a state-dependent energetic model in an ecosystem size-spectrum to ask whether prey availability (foraging) and risk of predation experienced by individual fish can explain observed diversity in life histories of fishes. We found that asymptotic growth emerged from size-based foraging and reproductive and mortality patterns in the context of ecosystem food web interactions. While more productive ecosystems led to larger body sizes, the effects of temperature on metabolic costs had only small effects on size. To validate our model, we ran it for abiotic scenarios corresponding to the ecological lifestyles of three tuna species, considering environments that included seasonal variation in temperature. We successfully predicted realistic patterns of growth, reproduction, and mortality of all three tuna species. We found that individuals grew larger when environmental conditions varied seasonally, and spawning was restricted to part of the year (corresponding to their migration from temperate to tropical waters). Growing larger was advantageous because foraging and spawning opportunities were seasonally constrained. This mechanism could explain the evolution of gigantism in temperate tunas. Our approach addresses variation in food availability and individual risk as well as metabolic processes and offers a promising approach to understand fish life-history responses to changing ocean conditions.
了解生长和繁殖将如何适应不断变化的环境条件是进化生态学中的一个基本问题，但预测特定分类群的反应具有挑战性。对气候变化对生活史进化的生理影响进行分析时，很少同时考虑其他假设机制，如大小依赖型觅食和被捕食风险，这些机制共同塑造了最优生长模式。为了测试这些机制之间的相互作用，我们将一个状态依赖的能量模型嵌入到一个生态系统大小谱中，以探究个体鱼类所经历的猎物可获得性（觅食）和被捕食风险是否能够解释观察到的鱼类生活史多样性。我们发现，在生态系统食物网相互作用的背景下，基于大小的觅食以及繁殖和死亡模式产生了渐近生长。虽然生产力更高的生态系统会导致更大的体型，但温度对代谢成本的影响对体型的影响很小。为了验证我们的模型，我们针对与三种金枪鱼物种的生态生活方式相对应的非生物情景运行该模型，考虑了包括温度季节性变化的环境。我们成功预测了所有三种金枪鱼物种的现实生长、繁殖和死亡模式。我们发现，当环境条件季节性变化时，个体长得更大，并且产卵被限制在一年中的部分时间（对应于它们从温带水域向热带水域的洄游）。长得更大是有利的，因为觅食和产卵机会受到季节性限制。这种机制可以解释温带金枪鱼巨型化的进化。我们的方法考虑了食物可获得性和个体风险的变化以及代谢过程，为理解鱼类生活史对不断变化的海洋条件的反应提供了一种有前景的方法。
