Behavioural physiology and fitness of anadromous migrating fish

成体淡水型太平洋鲑鱼(Oncorhynchus spp.)在能量上是昂贵的，在生理上也有压力。鱼类在从海洋进入淡水之前停止摄食几天到几周，并承担超过一半，往往更多的能量储备来到达产卵区。最初能量低，或压力、代谢功能障碍、疾病或极端环境(如高河温或流量)水平升高，可能会导致迁徙死亡或产卵受损。种群在进入淡水的时间、迁徙距离和海拔方面差异很大；因此，种群会遇到不同的海岸和河流条件。种群在能量使用、繁殖力、迁徙存活率和产卵成功率方面差异很大。而且，与其他物种相比，一些物种暴露在更极端的环境中，受到更高水平的剥削，以及与之相关的更高水平的捕食者和人类造成的伤害。因此，太平洋鲑鱼种群是研究迁徙经历对成熟和快速衰老的成年动物的健康影响以及对后代的影响的理想选择。总体而言，环境变异性以及成虫在迁徙前、迁徙过程中和迁徙后对个体生殖成功的作用还知之甚少。*我们的长期目标是更广泛地了解迁徙的成年太平洋鲑鱼的行为、生理、病原体载量和疾病之间的联系，了解这些因素如何影响繁殖成功和适应能力。我们的工作是在加拿大最大的野生三文鱼产地弗雷泽河流域BC进行的。我们研究的是红鲑鱼，这是最具商业价值和第二丰富的太平洋鲑鱼物种，以及粉红鲑鱼，最丰富的物种。我们将进行大型实验，并使用组织活检和基因组方法来研究不同的太平洋鲑鱼适合度指标是如何受到以下因素影响的：i)迁徙温度、成鱼经历的伤害和病原体的实验差异，ii)成鱼经历的迁徙环境的自然差异，以及iii)个体在迁徙前后的生理状况的差异。我们将在种群和物种之间进行I到III的比较。在这项研究中，我们将使用卵子、精子、胚胎、鱼苗和成体属性的不同测量作为适应结果的替代指标，并将这些指标与迁徙环境和迁徙生理状态联系起来。幼鲑鱼产量有相当大的年际变化，这不能用产卵数量变化的简单考虑来解释，因此必须涉及其他因素。我们的结果将突出成年产卵者的质量、条件和迁徙经验的重要性，并提供对代际后果和遗留影响的机械性理解。**

The homeward spawning migration of adult anadromous Pacific salmon (Oncorhynchus spp.) is energetically expensive and physiologically stressful. Fish stop feeding days to weeks before entering freshwater from the ocean and commit over half, and often much more, of energy reserves to reach spawning areas. Initially low energy, or elevated levels of stress, metabolic dysfunction, disease, or extreme environments (e.g. high river temperatures or discharge), may result in migration mortality or impaired spawning. Populations vary greatly in run timing into freshwater, migration distance and elevation; hence populations encounter different coastal and river conditions. Populations vary considerably in energy use, fecundity, migration survival and spawning success. And, some are exposed to more extreme environments and much higher levels of exploitation and associated higher levels of predator and human induced injury than others. Pacific salmon populations are thus ideal for examining the fitness consequences on mature and rapidly senescing adult animals of migration experiences and carry-over effects to offspring. In general, the role of environmental variability, and that of adult condition before, during and after the migration, to the reproductive success of individuals is poorly understood. ****Our long-term objective is to establish a broader understanding of the linkages among behaviour, physiology, pathogen loads and disease of migrating adult Pacific salmon in terms of how these influence reproductive success and fitness. Our work is conducted in the Fraser River watershed BC, the largest producer of wild salmon in Canada. We study sockeye, the most commercially valuable and second most abundant Pacific salmon species and pink salmon, the most abundant species. We will conduct large experiments and use tissue biopsy and genomic approaches to investigate how various proxies of fitness in Pacific salmon are influenced by: I) experimental variance in migration temperatures, wounding and pathogens experienced by adults, II) natural variance in the migration environment experienced by adults, and III) differences among individuals in their physiological condition before/after migration. We will compare I to III among populations and species. In this research we will use different measures of eggs, sperm, embryos, fry, and adult attributes as proxies for fitness' consequences and relate these to migration environment and migrant physiological state. There is considerable inter-annual variability in production of juvenile salmon which cannot be explained by simple considerations of variability in number of spawners, so other factors must be involved. Our results will highlight the importance of the quality, condition and migration experience of adult spawners and provide a mechanistic understanding of intergenerational consequences and carry-over effects. **