Pagel Thilo, Bekkevold Dorte, Pohlmeier Stefan, Wolter Christian, Arlinghaus Robert
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany,
Oecologia. 2015 Aug;178(4):951-65. doi: 10.1007/s00442-015-3301-y. Epub 2015 Apr 18.
Hatching early in the season is often assumed to elevate fitness, particularly in cannibalistic fish in which size-dependent predation mortality is a major selective force. While the importance of the thermal environment for the growth of fish is undisputed, the relevance of maternal effects for offspring growth in the wild is largely unknown. Otoliths of 366 age-0 pike (Esox lucius L.) were sampled in a natural lake over three seasons. All offspring were assigned to more than 330 potential mothers using 16 informative microsatellites. We found temperature and past maternal environment (as represented by juvenile growth rate), but not female total length, to jointly contribute to explain within- and among-season size variation in juvenile pike. While there was no statistical evidence for maternal effects on offspring growth rate, fast female juvenile growth positively correlated with the offspring length in early summer. One mechanism could be related to fast-growing females spawning somewhat earlier in the season. However, the more likely mechanism emerging in our study was that fast-growing females could have been in better condition prior to spawning, in turn possibly producing higher numbers of high-quality eggs. Our study is among the few to reveal carry-over effects related to past maternal environments on offspring performance in a naturally reproducing fish stock. At the same time, our study underscores recent arguments that size-dependent maternal effects may not be expressed in the wild and that early hatching does not generally produce size advantages in light of stochastically varying temperature conditions.
通常认为，在季节早期孵化能够提高适合度，尤其是在具有同类相食习性的鱼类中，因为体型依赖性捕食死亡率是一种主要的选择压力。虽然热环境对鱼类生长的重要性无可争议，但母体效应在野生环境中对后代生长的相关性却 largely unknown。在三个季节里，从一个天然湖泊中采集了366条0龄梭子鱼（Esox lucius L.）的耳石。使用16个信息丰富的微卫星将所有后代分配给330多个潜在的母亲。我们发现温度和过去的母体环境（以幼鱼生长速率表示），而非雌鱼的全长，共同促成了解释幼龄梭子鱼季节内和季节间的体型变化。虽然没有统计证据表明母体效应会影响后代的生长速率，但雌鱼幼鱼的快速生长与初夏时后代的体长呈正相关。一种机制可能与快速生长的雌鱼在季节稍早时产卵有关。然而，我们的研究中出现的更可能的机制是，快速生长的雌鱼在产卵前可能状况更好，进而可能产出数量更多的高质量卵。我们的研究是少数揭示过去母体环境对自然繁殖鱼类种群后代表现产生的遗留效应的研究之一。同时，我们的研究强调了最近的一些观点，即体型依赖性母体效应在野外可能不会表现出来，并且鉴于温度条件随机变化，早期孵化通常不会产生体型优势。
