Rapid movement and instability of an invasive hybrid swarm.
Rapid movement and instability of an invasive hybrid swarm.
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DOI：
10.1111/eva.12371
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发表时间：
2016-07
影响因子：
4.1
通讯作者：
Blum MJ
中科院分区：
文献类型：
--
作者：
Glotzbecker GJ;Walters DM;Blum MJ
引入非本地物种后出现的不稳定的杂交群体可以压倒本地同源物，但随着时间的推移，入侵杂交群体的稳定性尚未得到很好的记录。在这里，我们研究了最近形成的一个杂交群体的遗传变异和倾斜稳定性，该群体涉及库萨河上游流域的原生黑尾闪光鱼（Cyprinella venusta）和非原生红闪光鱼（C. lutrensis），该流域被广泛认为是水生生物多样性的全球热点。2005年至2011年之间的表型，多位点基因型和线粒体单倍型变异的检查显示，随着时间的推移，杂交种的比例有所增加，超过三分之一的采样个体在采样的最后一年表现出混合物。随着时间的推移，渐变群的比较表明，混合群一直在迅速向上游发展，但在下降和速度慢于从历史收集记录估计的速度。临床比较还表明，随着时间的推移，混合群体一直在扩大和缩小。此外，我们还记录了比以前的研究发现的更下游的红闪鱼和杂交鱼的存在，这表明库萨河流域的同源物，包括受威胁的蓝闪鱼（Cyprinella caerulea）的所有剩余种群，比以前认为的风险更大。
Unstable hybrid swarms that arise following the introduction of non‐native species can overwhelm native congeners, yet the stability of invasive hybrid swarms has not been well documented over time. Here, we examine genetic variation and clinal stability across a recently formed hybrid swarm involving native blacktail shiner (Cyprinella venusta) and non‐native red shiner (C. lutrensis) in the Upper Coosa River basin, which is widely considered to be a global hot spot of aquatic biodiversity. Examination of phenotypic, multilocus genotypic, and mitochondrial haplotype variability between 2005 and 2011 revealed that the proportion of hybrids has increased over time, with more than a third of all sampled individuals exhibiting admixture in the final year of sampling. Comparisons of clines over time indicated that the hybrid swarm has been rapidly progressing upstream, but at a declining and slower pace than rates estimated from historical collection records. Clinal comparisons also showed that the hybrid swarm has been expanding and contracting over time. Additionally, we documented the presence of red shiner and hybrids farther downstream than prior studies have detected, which suggests that congeners in the Coosa River basin, including all remaining populations of the threatened blue shiner (Cyprinella caerulea), are at greater risk than previously thought.