Departamento de Biología Funcional, Area de Genetica, Universidad de Oviedo, C/ Julian Claveria s/n 33006 Oviedo, Spain.
J Hered. 2010 Jul-Aug;101(4):461-8. doi: 10.1093/jhered/esq042. Epub 2010 May 7.
By genetic analysis of 1625 samples from 10 south European rivers, we have found that Atlantic salmon Salmo salar hybridize with sympatric brown trout S. trutta in the wild and provide the female in most heterospecific crosses. Hybrids exhibit reduced fertility and could be considered a wasted reproductive effort by salmon females. In 7 experiments involving salmon females, large brown trout males, and small salmon male sneakers, reproductive success of Atlantic salmon females mating with brown trout males was not significantly different from that of 5 experiments of females mating with conspecific males because small Atlantic salmon sneakers fertilized most ova (mean 93%) in salmon x trout matings. Although egg retention tended to be higher in heterospecific than in conspecific crosses (mean 5.7% vs. 20.5% respectively), mean offspring survival was 24.4% and 30.3%, respectively (t = 1.5 x 10(-8), not significant). Brown trout males taking on a courting role may benefit late-maturing females in absence or scarcity of anadromous salmon males because they play a protective role against disturbances from other fishes (including cannibal sneakers).
通过对来自 10 条南欧河流的 1625 个样本进行基因分析，我们发现野生状态下的大西洋鲑 Salmo salar 与同域分布的褐鳟 S. trutta 杂交，并为大多数异源杂交中的雌性提供精子。杂种表现出较低的生育能力，可以被认为是雌性鲑鱼浪费的繁殖努力。在涉及鲑鱼雌性、大型褐鳟雄性和小型鲑鱼雄性 sneaker 的 7 个实验中，与褐鳟雄性交配的大西洋鲑鱼雌性的繁殖成功率与与同种雄性交配的 5 个实验没有显著差异，因为小型大西洋鲑鱼 sneaker 受精了大多数卵子（平均 93%）在鲑鱼 x 鳟鱼的交配中。尽管异源杂交中的卵保留率往往高于同域杂交（分别为 5.7%和 20.5%），但平均后代存活率分别为 24.4%和 30.3%（t = 1.5 x 10(-8)，无显著差异）。扮演求偶角色的褐鳟雄性可能会受益于缺乏或稀缺溯河洄游雄性鲑鱼的晚熟雌性，因为它们扮演着保护角色，免受其他鱼类（包括同类相食的 sneaker）的干扰。
