Bekkevold D, Hansen M M, Loeschcke V
Institute of Biological Sciences, Department of Ecology & Genetics, University of Aarhus, DK-8000 Arhus C, Denmark.
Mol Ecol. 2002 Jan;11(1):91-102. doi: 10.1046/j.0962-1083.2001.01424.x.
Reproductive competition may lead to a large skew in reproductive success among individuals. Very few studies have analysed the paternity contribution of individual males in spawning aggregations of fish species with huge census population sizes. We quantified the variance in male reproductive success in spawning aggregations of cod under experimental conditions over an entire spawning season. Male reproductive success was estimated by microsatellite-based parentage analysis of offspring produced in six separate groups of spawning cod. In total, 1340 offspring and 102 spawnings distributed across a spawning season were analysed. Our results show that multiple males contributed sperm to most spawnings but that paternity frequencies were highly skewed among males, with larger males on average siring higher proportions of offspring. It was further indicated that male reproductive success was dependent on the magnitude of the size difference between a female and a male. We discuss our results in relation to the cod mating system. Finally, we suggest that the highly skewed distribution of paternity success observed in cod may be a factor contributing to the low effective population size/census population size ratios observed in many marine organisms.
生殖竞争可能导致个体间生殖成功率出现巨大偏差。在普查种群规模巨大的鱼类产卵群体中，极少有研究分析个体雄性的父权贡献。我们在整个产卵季节的实验条件下，对鳕鱼产卵群体中雄性生殖成功率的差异进行了量化。通过对六组单独产卵的鳕鱼所产后代进行基于微卫星的亲权分析，来估计雄性生殖成功率。总共分析了分布在一个产卵季节的1340个后代和102次产卵。我们的结果表明，多个雄性为大多数产卵贡献了精子，但雄性之间的父权频率高度不均，体型较大的雄性平均生育的后代比例更高。进一步表明，雄性生殖成功率取决于雌雄性之间体型差异的大小。我们结合鳕鱼的交配系统讨论了我们的结果。最后，我们认为在鳕鱼中观察到的父权成功高度不均的分布，可能是导致许多海洋生物有效种群规模/普查种群规模比率较低的一个因素。
