Causes and consequences of the trade-off between compensatory growth and swim performance in teleost fish

对于许多动物来说，越大越好。较大的体型降低了被捕食者吃掉的风险，也可能导致动物能够产生的后代数量增加。尽管增加身体大小有这些明显的好处，但越来越多的证据表明，大多数生物体并没有以生理上可能的最大速度生长，而且快速生长实际上可能会带来巨大的成本。补偿性生长（许多生物在一段时间的食物匮乏后出现的快速生长）为研究这些潜在成本提供了一种有用的手段，在鱼类中，经历了一段时间的生长补偿的个体在以后的生活中往往会表现出游泳能力的下降。虽然这样的成本可能对生存和繁殖成功产生重要影响，但补偿性生长和游泳能力受损之间权衡的潜在机制尚不清楚。也没有人知道鱼的补偿性生长反应的个体差异，以及个体之间的成本差异的程度。总的来说，由于我们缺乏知识，无法准确预测补偿性生长对个体鱼类生存和繁殖成功的影响，以及它对野生鱼类种群动态的影响。这种信息将是有价值的，特别是考虑到由于气候变化等因素，粮食供应波动的可能性增加。拟议的研究将检查肌肉纤维结构，生物化学，新陈代谢和游泳性能在个别鱼，以获得洞察负责生长速度和游泳性能之间的权衡机制。将进行额外的实验室研究，以检查捕食者的存在对个体的生长反应变化的影响，并研究补偿性生长对个体冒险行为和生殖成功的后果。最后，理论研究，利用个人为基础的数学模型将补充这些实验室实验，通过将vaccically-derived估计的变化，以调查的影响，在个人健身增长率的变化。总体而言，这项跨学科研究将使我们能够更好地了解鱼类快速增长成本的机械基础，以及这种权衡对行为和进化生态学的影响。

For many animal species, bigger is better. Larger body size reduces the risk of being consumed by predators, and can also lead to an increase in the number of offspring that an animal is able to produce. Despite these apparent benefits of increased body size, mounting evidence suggests that most organisms do not grow at the maximum rates that are physiologically possible, and that there may actually be significant costs associated with rapid growth. Compensatory growth (the rapid growth which occurs in many organisms after a period of food deprivation) provides a useful means to study these potential costs, and in fish, individuals that have undergone a period of growth compensation tend to display reduced swimming performance later in life. While such a cost could have an important influence on both survival and reproductive success, the underlying mechanism responsible for this trade-off between compensatory growth and impaired swimming ability is not understood. There is also nothing known about individual variation in the compensatory growth response in fishes, and the extent to which the costs may differ between individuals. Overall, our lack of knowledge makes it impossible to accurately predict the consequences of compensatory growth for the survival and reproductive success of individual fish, and its effects on the dynamics of wild fish populations. Such information would be valuable, especially considering the increased likelihood of fluctuations in food availability due to factors such as climate change. The proposed research will examine muscle fibre structure, biochemistry, metabolism, and swim performance in individual fish to gain insights into the mechanisms responsible for the trade-off between growth rate and swim performance. Additional laboratory studies will be performed to examine the influence of predator presence on individual variation in the growth response, and also to study the consequences of compensatory growth for individual risk-taking behaviour and reproductive success. Finally, theoretical studies utilizing individual-based mathematical models will compliment these laboratory experiments by incorporating empirically-derived estimates of variability to investigate the implications of variation in growth rate for individual fitness. Overall, this interdisciplinary study will allow us to better understand the mechanistic underpinnings of the costs of rapid growth in fish, and also the consequences of this trade-off for behavioural and evolutionary ecology.