Straying has been difficult to study directly in natural steelhead Oncorhynchus mykiss populations. We analyzed an opportunistic sample of seven adult steelhead from a small basin on the Big Sur coast of California to determine their life history traits, including whether they were strays. Otolith natural tags (⁸⁷Sr/⁸⁶Sr) and genetic stock identification indicated that all seven adults were strays from at least six different sources. Three adults strayed from nearby streams (<72 km) on the Big Sur coast, while three strayed from distant sources, including the Klamath River (680 km to the north); the source of one stray could not be identified. Six strays were progeny of steelhead mothers, but one was the offspring of a nonanadromous mother. Six were female and one was male, and all that could be genotyped were homozygous (n = 4) or heterozygous (n = 2) for the anadromy-associated haplotype in a migration-associated genomic region. While the opportunistic nature and small size of the sample prevents us from inferring the rate of straying into the basin, our study nonetheless demonstrates that steelhead may stray across greater distances than generally has been appreciated and that nonanadromous females can produce anadromous offspring that stray, thus providing connectivity among basins.

中文翻译：

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耳石天然标签和遗传种群鉴定揭示了加利福尼亚沿海小溪流中成年钢头鱼的流浪和生活史

很难直接在天然钢头Oncorhynchus mykiss种群中研究流浪。我们分析了来自加利福尼亚州大苏尔海岸的一个小盆地的 7 只成年钢头鱼的机会样本，以确定它们的生活史特征，包括它们是否是流浪者。耳石自然标签 ( ⁸⁷ Sr/ ⁸⁶Sr) 和遗传种群鉴定表明，所有七只成年人都来自至少六个不同的来源。三只成虫偏离了大苏尔海岸附近的溪流（<72 公里），而三只来自遥远的源头，包括克拉马斯河（以北 680 公里）；无法确定一只流浪狗的来源。六只流浪狗是铁头妈妈的后代，但其中一只是无名妈妈的后代。6 名女性，1 名男性，所有可以进行基因分型的都是纯合子 ( n  = 4) 或杂合子 ( n = 2) 对于迁移相关基因组区域中的解剖相关单倍型。虽然样本的机会主义性质和小规模阻止我们推断误入盆地的速度，但我们的研究仍然表明，钢头可能会比通常所认识的更远，并且非溯河雌性可以产生迷路的溯河后代，因此提供流域之间的连通性。