换位,出于保护目的的生物运动,如果遗传物质以新的方式在种群之间流动,可能会导致意外的基因渗入。BluemaskDarterEtheostomaakatulo是居住在CaneyFork河系统及其三个支流(CollinsRiver,洛基河,和CaneCreek)在田纳西州。BluemaskDarters的当前保护策略涉及将亲鱼的后代从柯林斯河(西部)转移到该物种已灭绝的Calfkiller河(东部)。在这项研究中,我们使用来自现有范围的ddRAD序列数据来根据种群结构评估这种易位策略,系统发育,和人口统计。我们还包括博物馆标本数据,以评估现存和灭绝种群之间的形态变化。我们的分析揭示了柯林斯河西部人口与洛基河东部人口之间的巨大遗传和表型差异,甘蔗溪,和上CaneyFork,两者拥有超过10万年前的共同祖先。此外,形态学分析对13个Calfkiller河标本中的12个进行了分类,其表型与东部人群一致。这些结果表明,当前的易位扰乱了两个定界种群之间的进化边界。相反,我们建议使用洛基河的少年重新填充Calfkiller河可以平衡人口统计的相互矛盾的特征,多样性,和分歧。除了保护,BluemaskDarter种群的微观地理结构为北美东部超多样化淡水鱼的系统地理增添了另一个难题。
Translocation, the movement of organisms for conservation purposes, can result in unintended introgression if genetic material flows between populations in new ways. The Bluemask Darter Etheostoma akatulo is a federally endangered species of freshwater fish inhabiting the Caney Fork River system and three of its tributaries (Collins River, Rocky River, and Cane Creek) in Tennessee. The current conservation strategy for Bluemask Darters involves translocating the progeny of broodstock from the Collins River (in the west) to the Calfkiller River (in the east) where the species had been extirpated. In this study, we use ddRAD sequence data from across the extant range to assess this translocation strategy in light of population structure, phylogeny, and demography. We also include museum specimen data to assess morphological variation among extant and extirpated populations. Our analyses reveal substantial genetic and phenotypic disparities between a western population in the Collins River and an eastern population encompassing the Rocky River, Cane Creek, and upper Caney Fork, the two of which shared common ancestry more than 100,000 years ago. Furthermore, morphological analyses classify 12 of 13 Calfkiller River specimens with phenotypes consistent with the eastern population. These results suggest that current translocations perturb the evolutionary boundaries between two delimited populations. Instead, we suggest that repopulating the Calfkiller River using juveniles from the Rocky River could balance conflicting signatures of demography, diversity, and divergence. Beyond conservation, the microgeographic structure of Bluemask Darter populations adds another puzzle to the phylogeography of the hyperdiverse freshwater fishes in eastern North America.