Easwaramoorthy Mellissa, Thompson William Andrew, Fraz Shamaila, Nederveen Joshua P, Hartenstein Peyton, Laframboise Lisa, Manzon Richard G, Somers Christopher M, Wilson Joanna Y
Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
J Exp Biol. 2025 Sep 16. doi: 10.1242/jeb.250164.
Temperate waters, such as the Great Lakes, are predicted to increase by 1°C every decade. Many poikilothermic fish thermoregulate behaviourally, moving to more suitable thermal environments. Embryos are incapable of locomotion and may be exposed to non-optimal temperatures during development. Previous work has suggested that temperature increases during embryogenesis can alter growth rates in fish. However, less is known of whether these early-life exposures to elevated temperatures can impart alterations to the phenotypic plasticity of performance traits, particularly in temperate species. We hypothesized that increased embryonic incubation temperature would diminish the larval performance of yellow perch (Perca flavescens), a critical cultural and ecological species of fish. We reared yellow perch embryos at 12°C, 15°C, or 18°C until hatching; after hatching, the temperature was raised to a common garden 18°C, their preferred post-hatch temperature. We assessed exploratory behaviour, metabolism (oxygen consumption), and cardiac performance throughout early development. At hatch, 12°C fish exhibited the greatest swimming activity, with 18°C fish consuming the least oxygen and possibly experiencing mitochondrial dysfunction. Cardiac development was more advanced at hatch in 18°C fish. Yet, warmer incubated fish had diminished movement and increased oxygen consumption at 20 days post-hatch, demonstrating long-term disruptions of increased temperature in the embryonic environment. Overall, elevations in rearing temperature may cause metabolic dysfunction and behavioural alterations, potentially impacting the survival of yellow perch.
诸如五大湖这样的温带水域预计每十年温度会上升1摄氏度。许多变温鱼类会通过行为进行体温调节，转移到更适宜的热环境中。胚胎无法自主移动，在发育过程中可能会暴露于非最适宜的温度下。先前的研究表明，胚胎发育期间温度升高会改变鱼类的生长速度。然而，对于这些早期处于高温环境下的经历是否会改变性能性状的表型可塑性，尤其是在温带物种中，我们了解得还较少。我们假设，胚胎孵化温度升高会降低黄鲈（Perca flavescens）幼体的性能，黄鲈是一种重要的养殖和生态鱼类。我们将黄鲈胚胎分别在12°C、15°C或18°C下饲养至孵化；孵化后，将温度升高至共同环境温度18°C，这是它们孵化后偏好的温度。我们在整个早期发育过程中评估了探索行为、新陈代谢（耗氧量）和心脏性能。孵化时，12°C饲养的鱼表现出最强的游泳活动，18°C饲养的鱼耗氧量最少，可能存在线粒体功能障碍。18°C饲养的鱼在孵化时心脏发育更成熟。然而，孵化时处于较高温度环境下的鱼在孵化后20天运动能力下降且耗氧量增加，这表明胚胎环境温度升高会产生长期干扰。总体而言，饲养温度升高可能会导致代谢功能障碍和行为改变，可能会影响黄鲈的生存。
