Reed Thomas E, Wynne Robert, Coughlan Jamie, Gargan Patrick, Kaufmann Joshka, Phillips Karl P, Rinaldo Adrian, Poole Russell, McGinnity Philip
School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.
Environmental Research Institute, University College Cork, Cork, Ireland.
J Fish Biol. 2025 Jun;106(6):1816-1830. doi: 10.1111/jfb.16068. Epub 2025 Feb 6.
We undertook a common garden experiment in the Burrishoole catchment, western Ireland, to test for heritable life-history differences among neighboring brown trout (Salmo trutta L.) populations that exhibit neutral genetic divergence. Experimental crosses were made using either local females (obtained from a below-waterfalls section of the Rough River within the Burrishoole) or females from the Erriff River-a neighboring catchment that currently produces a stronger run of anadromous migrants than the Burrishoole. Each female was mated to three different types of males: Rough Below-Falls, Rough Above-Falls (resident males obtained from above the waterfalls), and Erriff. Offspring from the resulting six crosses were introduced as unfed fry into a stretch of the Rough River bounded upstream by the waterfalls and downstream by a Wolf-type fish trap (Rough River Downstream Trap, RRDT). Genetic parentage analysis (16 microsatellite markers) was then used to assign offspring sampled at various time points and locations back to cross type. No differences in parr survival rates (electrofishing in the Rough River) were found among the crosses, but parr moving downstream (intercepted at the RRDT) were skewed toward the Erriff female × Erriff male cross, with a deficit assigning to the Rough Below-Falls female × Rough Above-Falls male cross. Smolts leaving fresh water (sampled at two sea-entry traps) were assigned disproportionately to crosses involving one or two Erriff parents. Offspring from pure Burrishoole crosses were more likely to become putative spawners than those from crosses involving one or two Erriff parents, pointing toward possible local adaptation. These results are consistent with heritable variation in migratory tendencies-a key aspect of intraspecific biodiversity that warrants protection-and with previous suggestions that the Burrishoole system may have evolved recently toward reduced anadromy following a novel and catastrophic anthropogenic change.
我们在爱尔兰西部的伯里肖尔集水区进行了一项共同花园实验，以测试表现出中性遗传分化的相邻褐鳟（Salmo trutta L.）种群之间可遗传的生活史差异。实验杂交使用了当地雌性（从伯里肖尔内的拉夫河瀑布下游段获得）或来自埃尔里夫河的雌性——这是一个相邻的集水区，目前洄游性迁徙鱼类的洄游规模比伯里肖尔更强。每只雌性与三种不同类型的雄性交配：拉夫河瀑布下游雄性、拉夫河瀑布上游雄性（从瀑布上游获得的定居雄性）和埃尔里夫雄性。将所得六个杂交组合的后代作为未投喂的鱼苗引入拉夫河的一段区域，该区域上游以瀑布为界，下游以狼型鱼陷阱（拉夫河下游陷阱，RRDT）为界。然后使用遗传亲权分析（16个微卫星标记）将在不同时间点和地点采集的后代归为杂交类型。在杂交组合中未发现仔鱼存活率（在拉夫河进行电捕鱼）存在差异，但向下游移动的仔鱼（在RRDT处拦截）偏向于埃尔里夫雌性×埃尔里夫雄性杂交组合，而拉夫河瀑布下游雌性×拉夫河瀑布上游雄性杂交组合的仔鱼数量不足。离开淡水的幼鲑（在两个入海口陷阱采集）不成比例地归为涉及一到两个埃尔里夫亲本的杂交组合。纯伯里肖尔杂交组合的后代比涉及一到两个埃尔里夫亲本的杂交组合的后代更有可能成为假定的产卵者，这表明可能存在局部适应性。这些结果与洄游倾向的可遗传变异一致——这是种内生物多样性的一个关键方面，值得保护——也与之前的观点一致，即伯里肖尔系统可能在经历了一次新的灾难性人为变化后，最近朝着减少溯河洄游的方向进化。
