Franckowiak Ryan P, Ridgway Mark S, Wilson Chris C
Environmental and Life Sciences Graduate Program Trent University Peterborough ON Canada.
Harkness Laboratory of Fisheries Research Ontario Ministry of Natural Resources and Forestry Aquatic Research and Monitoring Section Trent University Peterborough ON Canada.
Ecol Evol. 2017 Sep 20;7(21):8864-8875. doi: 10.1002/ece3.3423. eCollection 2017 Nov.
Mating systems are an important factor influencing the variance in reproductive success among individuals within natural populations and thus have important ecological and evolutionary implications. We used molecular pedigree reconstruction techniques with microsatellite DNA data to characterize the genetic mating system and mate selection in adult smallmouth bass spawning in Lake Opeongo. The genetic mating system of smallmouth bass in this system can be characterized as predominantly monogamous with a low rate of polygynandry particularly among larger individuals. Iteroparous individuals showed a complete absence of interannual mate fidelity, presumably due to the low annual return rate of spawning adults. Within a season, individuals from both sexes pursued additional mating opportunities with males showing greater variance in mate number than females. Female mate selection appeared to be largely random with little evidence for elevated levels of inbreeding in this population. Multiple mating females pursued additional males to whom they were less related than the first male with which they spawned within a given season, however, this pattern varied among years. The mating pattern observed in this population would likely limit the strength of sexual selection and thus could account for the lack of sexual dimorphism and the absence of alternative reproductive tactics in this species.
交配系统是影响自然种群中个体繁殖成功率差异的一个重要因素，因此具有重要的生态和进化意义。我们利用微卫星DNA数据的分子谱系重建技术，对奥彭戈湖中小口黑鲈成鱼产卵时的遗传交配系统和配偶选择进行了特征描述。该系统中小口黑鲈的遗传交配系统主要表现为一夫一妻制，多偶制发生率较低，尤其是在体型较大的个体中。多次繁殖的个体完全没有年度配偶忠诚度，推测这是由于产卵成鱼的年回游率较低。在一个繁殖季节内，雌雄个体都会寻求额外的交配机会，雄性的配偶数量差异比雌性更大。雌性配偶选择似乎很大程度上是随机的，几乎没有证据表明该种群存在近亲繁殖水平升高的情况。多次交配的雌性会追求额外的雄性，在特定季节内，它们与这些雄性的亲缘关系比与它们首次交配的雄性更远，然而，这种模式在不同年份有所不同。在这个种群中观察到的交配模式可能会限制性选择的强度，因此可以解释该物种缺乏两性异形和替代繁殖策略的现象。
