The causes and consequences of sex differences and body size variation in fish

鱼类性别差异和体型差异的原因和后果

• 批准号: RGPIN-2021-03057
• 负责人: Raby, Graham
• 金额: $ 2.4万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742354
• 关键词: causes; consequences; sex; differences; body

Energy links physiology, behaviour, growth, and reproductive output in all animals. In ectotherms like fish, variation in temperature is a key driver of energy use (metabolism), which can affect how animals take in and transfer nutrients through their ecosystem. The recent proliferation of telemetry tracking, animal-borne data loggers, and respirometry provides an opportunity to make our understanding of animal energetics more powerful in ways that can help us manage fisheries in a warming climate. One knowledge gap in fish energetics is how energy use and its relationship with temperature differs between male and female fish, and among fish of different size/age classes. In many animals including some fishes, sex and body size are connected because of sexual size dimorphism (SSD). In fishes, SSD can occur in either direction, but more commonly there is evolutionary pressure for females to grow larger than males because large females have disproportionately higher reproductive output (i.e., reproductive hyperallometry). For example, in walleye-among the most important fishes in North America-females reach sizes about 20% larger than those of males. While there is a widely accepted evolutionary explanation for SSD, we know surprisingly little about how females achieve higher growth. The `mystery' of SSD is relevant to ecological processes but also to unknowns about fish growth and body size variation, including the problem reproductive hyperallometry poses for existing growth models and a lack of clarity about what mechanisms are causing fish to `shrink' with climate warming. Collectively, there remains considerable room for discovery about processes driving growth, variation in body size, and their connection to sex differences and thermal tolerance in fishes. My program has a focus on wild freshwater fishes and will quantify patterns of thermal tolerance and preference, growth, feeding ecology/physiology, and metabolic rate in wild fishes in field settings and in laboratory experiments. The program will focus partly on walleye and yellow perch as models (two species that exhibit SSD), in addition to the invasive round goby (SSD in the reverse direction; males grow to be larger) and stream-resident brook trout (no SSD, and a contrasting coldwater life history). The program consists of three overall projects. The first project will investigate the energetic mechanisms underlying sexual size dimorphism in walleye and yellow perch, using a comparative field- and lab-based approach. The second project focuses on using bioenergetic models, updated based on the data obtained in the first project, to predict changes to walleye populations with climate warming and explore the impacts of SSD on food webs. The third project focuses in on the question of how thermal performance windows (also called thermal envelopes) change across sizes, life stages, and between sexes in species with and without SSD.

能量与所有动物的生理、行为、生长和生殖输出有关。在鱼类等外温动物中，温度的变化是能量使用（代谢）的关键驱动因素，这会影响动物如何通过生态系统吸收和转移营养。最近遥测跟踪，动物携带的数据记录器和呼吸测量的扩散提供了一个机会，使我们对动物能量学的理解更加强大，可以帮助我们在气候变暖的情况下管理渔业。鱼类能量学中的一个知识缺口是雄性和雌性鱼类之间以及不同大小/年龄组的鱼类之间的能量使用及其与温度的关系如何不同。在许多动物中，包括一些鱼类，性别和身体大小是联系在一起的，因为性别大小二态性（SSD）。在鱼类中，SSD可以发生在任何一个方向上，但更常见的是雌性比雄性长得更大的进化压力，因为大的雌性具有不成比例的更高的生殖输出（即，生殖超异速生长）。例如，在北美最重要的鱼类之一的海象中，雌性海象的体型比雄性海象大20%。虽然对SSD有一个广泛接受的进化解释，但我们对女性如何实现更高的增长知之甚少。SSD的“奥秘”与生态过程有关，但也与鱼类生长和体型变化的未知因素有关，包括生殖超异速生长对现有生长模型造成的问题，以及对导致鱼类随着气候变暖而“萎缩”的机制缺乏明确性。总的来说，仍然有相当大的空间发现驱动生长的过程，身体大小的变化，以及它们与鱼类性别差异和耐热性的联系。我的计划有一个重点野生淡水鱼，并将量化的热耐受性和偏好，生长，喂养生态/生理学，并在野外环境和实验室实验中的野生鱼类的代谢率的模式。该计划将部分集中在walleye和黄鲈鱼作为模型（两个物种表现出SSD），除了入侵的圆虾虎鱼（SSD在相反的方向;男性成长为更大）和流居民溪鳟鱼（没有SSD，和对比冷水生活史）。该计划包括三个整体项目。第一个项目将调查的活力机制的性别大小二型性的大眼和黄鲈鱼，使用比较领域和实验室为基础的方法。第二个项目的重点是使用生物能量模型，更新的基础上获得的数据在第一个项目，预测变化的海象种群与气候变暖，并探讨SSD对食物网的影响。第三个项目的重点是热性能窗口（也称为热信封）如何在有和没有SSD的物种中跨大小，生命阶段和性别变化的问题。