Invasive alien species are a major driver of biodiversity loss, with their impacts potentially more intense when complexes of cryptic species are involved. In freshwaters, the anthropogenic manipulation of fish communities has resulted in altered fish communities, and in Europe has increased the complexity of Phoxinus species assemblages. Here, we investigated the Phoxinus communities of the westernmost part of the Po river basin, where adjacent freshwater ecosystems (Alpine high-altitude lakes and lowland streams) are representative of different management strategies (i.e. manipulated fish communities via stocking in Alpine lakes vs. natural populations in streams). We tested the genetic composition of the cryptic Phoxinus populations inhabiting these waters, as the species are morphologically indistinct. Sequences of the mitochondrial cytochrome oxidase I (COI) were obtained from 239 specimens, with the results indicating that 17 Alpine high-altitude lakes are now populated by a complex of Phoxinus species, comprising P. septimaniae (native to the Mediterranean area of France), P. csikii (native to the Central Balkans) and P. lumaireul (native to the North Adriatic Sea basins). Their introduction resulted from their use as angling live baits. Minnow populations in lowland streams were primarily comprised of native P. lumaireul, with only a single P. csikii specimen detected. While nuclear sequences of the recombination activating gene 1 (RAG1) marker were not useful for tracking the presence of alien alleles in these stream populations, the COI data emphasised the importance of using molecular tools to investigate cryptic species complexes that have been modified by anthropogenic activities.

外来入侵物种是生物多样性丧失的主要驱动力，当涉及到隐秘物种的复合体时，其影响可能会更大。在淡水中，对鱼类群落的人为操纵导致鱼类群落的改变，而在欧洲，磷辛属物种组合的复杂性增加。在这里，我们调查了Po河流域最西部的Phoxinus群落，其中相邻的淡水生态系统（高山高海拔湖泊和低地溪流）代表了不同的管理策略（即通过在高山湖泊中进行放养而对鱼类进行操控而对自然界进行操控）溪流中的人口）。我们测试了隐性福克斯的遗传组成这些物种在形态上不清楚，因此居住在这些水域中的种群。从239个标本中获得了线粒体细胞色素氧化酶I（COI）的序列，结果表明，现在已经有17种高山高海拔湖泊被一种由Phoxinus物种组成的复合体所组成，其中包括P. septimaniae（原产于法国地中海地区） ，Ps csikii（原产于巴尔干中部）和P. lumaireul（原产于北亚得里亚海盆地）。它们的引入是由于它们被用作钓鱼活饵。低地溪流中的鱼种群主要由原生的P. lumaireul组成，只有一个Ps csikii标本检测到。尽管重组激活基因1（RAG1）标记的核序列不能用于追踪这些流种群中外来等位基因的存在，但COI数据强调了使用分子工具研究已被人为活动修饰的隐性物种复合物的重要性。 。