Phylogeography, speciation and conservation genetics of patagonian fishes

我们的目标是研究巴塔哥尼亚本地鱼类的比较系统地理。南安第斯山脉在中新世(约23年前)开始抬升，分隔了东西流动的水系，影响了相关生物群的系统地理格局。由此产生的系统地理模式随后受到更新世反复出现的冰期和间冰期(1.8-10000 BP)和火山作用的影响。在最后一次冰川盛期，一块冰盖覆盖了距离拉特1800公里的巴塔哥尼亚安第斯山脉。35度S到56度S。这块冰盖到达了拉特以南安第斯山脉(太平洋)以西的大陆架边缘。因此，巴塔哥尼亚动植物的遗传多样性可能反映一种影响等级，更新世和全新世期间气候变化和火山活动的背离模式叠加在安第斯造山作用产生的古老背离足迹上。我们将集中在Galaxiidae的系统地理上，Galaxiidae是巴塔哥尼亚地区由三个广泛分布的物种(Galaxias platei、G.maculatus和Aploiton Zebra)和其他地理分布较有限的鱼类代表的一群鱼。G.platei是一种内陆物种，存在于冰后期湖泊的深水中。斑纹夜蛾和斑纹夜蛾是小型滨海物种，而斑纹夜蛾则表现为内陆型和泛泛型。将使用线粒体和核DNA基因座比较这三个物种的系统地理模式。对从生态系统内不同物种收集的遗传数据应用统计、系统地理和联合方法，将为生态群落的演变提供宝贵的洞察。巴塔哥尼亚鱼类动物群的多样性受到二十世纪初引入的鲑鱼的竞争和捕食的威胁，更严重的是，受到逃逸的水产养殖鲑鱼的威胁，预计随着该区域水产养殖业的不断扩大，逃逸三文鱼的影响将增加。我们的研究将证明对基于知识的保护和管理优先事项的发展是有用的。

Our objective is to examine the comparative phylogeography of the native fishes of Patagonia. The uplift of the southern Andes beginning in the Miocene (ca. 23 MYA), separated east and west flowing drainage systems and influenced the phylogeographic patterns of the associated biota. The resulting phylogeographic patterns were subsequently affected by the recurring glacial and interglacial periods of the Pleistocene (1.8 MYA - 10,000 BP) and by volcanism. During the Last Glacial Maximum an ice sheet covered the Patagonian Andes along 1800 km from Lat. 35ºS to 56ºS. This ice sheet reached the edge of the continental shelf west of the Andes (Pacific) south of Lat. 42ºS. Genetic diversity for the Patagonian flora and fauna might therefore be expected to reflect a hierarchy of influences, with patterns of divergence from climate change and volcanisms during the Pleistocene and Holocene layered onto ancient divergence footprints produced by the Andean orogeny. We will focus on the phylogeography of the Galaxiidae, a group of fish represented in Patagonia by three widespread species: (Galaxias platei, G. maculatus, and Aplochiton zebra) and others of more restricted geographic distribution. G. platei is a landlocked species present in the deep waters of postglacial lakes. G. maculatus and A. zebra are small littoral species with G. maculatus exhibiting landlocked and diadromous forms. Phylogeographic patterns will be compared across the three species using mitochondrial and nuclear DNA loci. The application of statistical phylogeographic and coalescent methods on genetic data collected from various species within ecosystems will provide valuable insight into the evolution of ecological communities. The diversity of the Patagonian fish fauna is threatened by competition and predation by salmonids introduced during the early twentieth century, and more recently and more critically, by escaped aquaculture salmon, the influence of which is expected to increase with the ever expanding aquaculture industry in the region. Our research will prove useful for the development of knowledge based conservation and management priorities.