Penney Heather D, Keefe Donald G, Perry Robert C, Purchase Craig F
Department of Biology Memorial University St. John's Newfoundland and Labrador Canada.
Department of Fisheries, Forestry and Agriculture Government of Newfoundland and Labrador Newfoundland and Labrador Corner Brook Canada.
Ecol Evol. 2022 Dec 15;12(12):e9636. doi: 10.1002/ece3.9636. eCollection 2022 Dec.
Initial body size can indicate quality within-species, with large size increasing the likelihood of survival. However, some populations or individuals may have body size disadvantages due to spatial/temporal differences in temperature, photoperiod, or food. Across-populations, animals often have locally adapted physiology to compensate for relatively poor environmental influences on development and growth, while within-population individual behavioral adjustments can increase food intake after periods of deprivation and provide opportunities to catch up (growth compensation). Previous work has shown that growth compensation should include within-population differences related to short growing seasons due to delayed hatch time. We tested the hypothesis that individual fish that hatch later grow faster than those that hatch earlier. The relative magnitude of such a response was compared with growth variation among populations. We sampled young of the year Arctic charr and brook trout from five rivers in northern Labrador. Daily increments from otoliths were used to back-calculate size to a common age and calculate growth rates. Supporting the hypothesis, older fish were not larger at capture than younger fish because animals that hatched later grew faster, which may indicate age-based growth compensation.
初始体型可以表明物种内部的质量，体型较大增加了生存的可能性。然而，由于温度、光周期或食物的时空差异，一些种群或个体可能存在体型劣势。在不同种群中，动物通常具有局部适应的生理机能，以弥补环境对发育和生长的相对不利影响，而在种群内部，个体的行为调整可以在一段时间的食物匮乏后增加食物摄入量，并提供追赶生长的机会（生长补偿）。先前的研究表明，生长补偿应包括种群内部因孵化时间延迟而导致生长季节较短的差异。我们检验了一个假设，即孵化较晚的个体鱼比孵化较早的个体鱼生长得更快。将这种反应的相对幅度与不同种群间的生长差异进行了比较。我们从拉布拉多北部的五条河流中采集了当年的北极红点鲑和溪鳟幼鱼。利用耳石的每日生长增量来反推到相同年龄时的体型，并计算生长率。支持这一假设的是，捕获时年龄较大的鱼并不比年龄较小的鱼体型大，因为孵化较晚的动物生长得更快，这可能表明存在基于年龄的生长补偿。
