INFLUENCE OF INDIVIDUAL BODY SIZE AND VARIABLE THRESHOLDS ON THE INCIDENCE OF A SNEAKER MALE REPRODUCTIVE TACTIC IN ATLANTIC SALMON
INFLUENCE OF INDIVIDUAL BODY SIZE AND VARIABLE THRESHOLDS ON THE INCIDENCE OF A SNEAKER MALE REPRODUCTIVE TACTIC IN ATLANTIC SALMON
复制标题
个体体型和可变阈值对大西洋鲑鱼雄性繁殖策略发生率的影响
DOI：
10.1111/j.0014-3820.2004.tb01580.x
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发表时间：
2004
影响因子：
4.8
通讯作者：
J. Dodson
中科院分区：
文献类型：
--
作者：
N. Aubin‐Horth;J. Dodson
摘要在条件策略模型中，生殖表型的差异取决于个体的条件是高于还是低于遗传决定的阈值。导致个体表达生殖策略的遗传和环境因素的相对贡献还没有得到很好的理解。在目前的实地研究中，我们确定了大西洋鲑鱼(Salmo Salar)中发育成熟的Parr表型的雄鱼和不发育成熟的Parr表型的雄鱼之间的条件差异。我们还研究了该阈值在种群中的一致性。我们连续四年在六个不同的地点对同一种群中一岁时成熟的Parr和未成熟的雄性进行抽样。我们的研究为基因和环境对生殖策略表达的交互作用提供了一个例子。在孵化(羽化)后20天，未来成熟的PARR的体型显著大于未来未成熟的雄性，这表明所采用的策略中可能有亲本效应成分，因为在此之前没有发生外源摄食。羽化时的大小优势在一年生的次年春季一直保持不同程度，因此暗示了策略表达的环境成分的存在。我们的结果支持这一观点，即在条件策略中，雄性所面临的环境和他在生殖时刻的状况始终不能预测他的后代所面临的环境，也不能预测他们通过表达与父亲相同的策略而获得的适合度。此外，一个地点较大的平均大小并不总是转化为较高比例的成熟PAR，因此支持这样的假设，即同一种群内不同栖息地的阈值不同。
Abstract In the conditional strategy model, divergence in reproductive phenotypes depends on whether the individual's condition is above or below a genetically determined threshold. The relative contribution of the genetic and environmental components that lead to the expression of a reproductive tactic by an individual is not well understood. In the present field study, we determined when condition diverged between males that develop the mature parr phenotype and those that do not in Atlantic salmon (Salmo salar). We also investigated the uniformity of the threshold value in the population. We sampled mature parr and immature males at age one, of the same population at six different sites for four consecutive years. Our study provides an example of the interaction of genotype and environment on the expression of a reproductive tactic. Size was significantly greater for future mature parr than for future immature males as early as 20 days after hatching (emergence), suggesting that there may be a parental effect component in the tactic adopted, since no exogenous feeding takes place before this time. Size advantage at emergence was maintained through the next spring at age one to different degrees depending on the year, thus suggesting the presence of an environmental component of tactic expression. Our results support the contention that within the conditional strategy, the environment faced by a male and his condition at the moment of reproduction consistently predicts neither the environment faced by his offspring nor the fitness they will obtain by expressing the same tactic as their father. Furthermore, higher mean size at a site did not always translate into a higher proportion of mature parr, therefore supporting the hypothesis that thresholds vary across habitats within the same population.