Massive fish introductions have taken place throughout much of the world, mostly over the last 70 years, and present a major threat to the genetic diversity of native fishes. Introductions have been reported for European Phoxinus, a ubiquitous small cyprinid that populates a wide variety of habitats. Species delineation in European Phoxinus has proven difficult with one reason being ranges of distribution that often traverse drainage boundaries. The present study combines recent samples with museum samples to better understand the current distribution of Phoxinus species and their distributions prior to the massive introductions of fishes in Europe, and to evaluate the use of museum specimens for species distribution studies. For these purposes, genetic lineages from sites collected prior to 1900 (n = 14), and between 1900 and 1950 (n = 8), were analysed using two mitochondrial and nuclear markers. Although possible fish introductions were detected, our results show that the distribution of genetic lineages of museum samples is comparable to that of the extant lineages of European Phoxinus present in those areas. These observations suggest that in the studied ranges the distribution of Phoxinus lineages has been driven by natural processes.

中文翻译：

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欧洲小鱼穿越时空：博物馆藏品有助于对淡水鱼类物种引入的遗传评估（鲤科：Phoxinus 物种复合体）

世界大部分地区都发生了大规模的鱼类引进，主要是在过去的 70 年中，对本地鱼类的遗传多样性构成了重大威胁。已经报道了欧洲 Phoxinus 的引入，这是一种无处不在的小型鲤科动物，生活在各种栖息地。欧洲 Phoxinus 中的物种划分已被证明是困难的，原因之一是分布范围经常跨越流域边界。本研究将最近的样本与博物馆样本相结合，以在欧洲大量引入鱼类之前更好地了解 Phoxinus 物种的当前分布及其分布，并评估博物馆标本在物种分布研究中的使用。出于这些目的，来自 1900 年之前 (n = 14) 和 1900 年至 1950 年之间 (n = 8) 的地点收集的遗传谱系，使用两种线粒体和核标记进行分析。尽管检测到可能的鱼类引进，但我们的结果表明，博物馆样本的遗传谱系分布与这些地区现存的欧洲 Phoxinus 谱系的分布相当。这些观察结果表明，在研究范围内，Phoxinus 谱系的分布是由自然过程驱动的。