Adoption of alternative migratory tactics: a view from the ultimate mechanism and threshold trait changes in a salmonid fish
Adoption of alternative migratory tactics: a view from the ultimate mechanism and threshold trait changes in a salmonid fish
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采用替代性洄游策略：从鲑鱼的最终机制和阈值性状变化来看
DOI：
10.1111/oik.03715
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发表时间：
2018
期刊：
影响因子：
3.4
通讯作者：
Morita Kentaro
中科院分区：
文献类型：
--
作者：
Sahashi Genki;Morita Kentaro
部分移徙是一种常见的移徙形式，即一部分人口移徙，而其余人口作为居民留下来。部分迁移的替代迁移策略（AMTs）通常由多基因阈值性状决定。然而，驱动阈值性状群体间变异的最终机制还没有得到很好的理解。我们提出了一个简单的示意图模型来解释阈值性状如何在相反的自然和人工选择力下随健身结果而变化。我们进行了现场试验，以评估迁移困难（作为一种自然选择力）和选择性圈养繁殖（作为一种人工选择力）的阈值特性的部分洄游鱼的影响。沙里河系统中的雄性马苏鲑虹鳟鱼的AMT分为三个种群类别的孵化场，野生/瀑布上方，野生/瀑布下方（对照）。野生/以上的瀑布鲑鱼生活在一个高迁移成本的情况下，和阈值特性改变的方向，促进居住。在孵化场鲑鱼，这是由移民选择性圈养繁殖，阈值特性改变的方向，促进迁移。与此相反，多莉瓦登charrSalvelinus malma显示只有居民战术，和阈值特性没有差异的人口之间的瀑布以上和以下，表明环境并没有解释阈值特性的变化。我们的研究结果支持该模型，并表明，相反的自然和人工选择的力量驱动的阈值特性和迁移模式在所研究的物种的变化。我们的最终机制的概念框架可能有助于更好地理解采用AMT和生产的不同种内性状的迁徙动物。
Partial migration, in which a portion of the population migrates while the rest of the population remains as residents, is a common form of migration. Alternative migratory tactics (AMTs) of partial migration are often determined by polygenic threshold traits. However, the ultimate mechanisms that drive inter‐population variations in threshold traits are not well understood. We present a simple schematic model to explain how the threshold trait changes with fitness consequences under opposing natural and artificial selection forces. We conducted a field test to evaluate the effects of migration difficulty (as a natural selective force) and selective captive breeding (as an artificial selective force) on threshold traits of a partially migratory fish. Male masu salmonOncorhynchus masouin the Shari River system have AMTs divided into three population categories of hatchery, wild/above the waterfall, and wild/below the waterfall (control). The wild/above the waterfall salmon live in a high‐migration‐cost situation, and the threshold trait changed in a direction that promoted residency. In hatchery salmon, which are produced by migrant‐selective captive breeding, the threshold trait changed in a direction that promoted migration. In contrast, Dolly Varden charrSalvelinus malmadisplayed only resident tactics, and the threshold trait did not differ between the populations above and below the waterfall, indicating that environment did not explain the variation in the threshold trait. Our results support the model and suggest that opposing natural and artificial selection forces drive variations in the threshold traits and migratory patterns in the studied species. Our conceptual framework for the ultimate mechanism may help to better understand adoption of AMTs and production of diverse intraspecific traits in migratory animals.