Hrbek Tomas, Meliciano Natasha V, Zuanon Jansen, Farias Izeni P
Laboratório de Evolução e Genética Animal, Departmento de Genética, Instituto de Ciências Biológicas, Universidade Federal do Amazonas, Manaus, Brazil.
Instituto de Saúde e Biotecnologia, Universidade Federal do Amazonas, Coari, Brazil.
Front Genet. 2018 Aug 14;9:295. doi: 10.3389/fgene.2018.00295. eCollection 2018.
Rapids and waterfalls, and their associated fauna and flora are in peril. With the construction of each new hydroelectric dam, more rapids and waterfalls are destroyed, leading to the disappearance of associated fauna and flora. Areas of rapids harbor distinct, highly endemic rheophilic fauna and flora adapted to an extreme environment. Rheophilic habitats also have disjunct distribution both within and across rivers. Rheophilic habitats thus represent islands of suitable habitat separated by stretches of unsuitable habitat. In this study, we investigated to what extent, if any, species of cichlid and anostomid fishes associated with rheophilic habitats were structured among the rapids of Araguaia River in the Brazilian Amazon. We tested both for population structuring as well as non-random distribution of lineages among rapids. Eight of the nine species had multiple lineages, five of these nine species were structured, and three of the eight species with multiple lineages showed non-random distribution of lineages among rapids. These results demonstrate that in addition to high levels of endemicism of rheophilic fishes, different rapids even within the same river are occupied by different lineages. Rheophilic species and communities occupying different rapids are, therefore, not interchangeable, and this realization must be taken into account when proposing mitigatory/compensatory measures in hydroelectric projects, and in conservation planning.
急流和瀑布及其相关的动植物正处于危险之中。随着每一座新的水电大坝的建设，更多的急流和瀑布被破坏，导致相关动植物的消失。急流区域拥有独特的、高度地方特有的适应极端环境的喜流动植物。喜流栖息地在河流内部和不同河流之间也具有间断分布。因此，喜流栖息地代表了被大片不适宜栖息地隔开的适宜栖息地岛屿。在本研究中，我们调查了与喜流栖息地相关的丽鱼科和甲鲶科鱼类物种在巴西亚马逊地区阿拉瓜亚河的急流中在何种程度上（如果有的话）存在结构差异。我们测试了种群结构以及急流之间谱系的非随机分布情况。九个物种中的八个有多个谱系，这九个物种中的五个有结构差异，八个有多个谱系的物种中的三个在急流之间显示出谱系的非随机分布。这些结果表明，除了喜流鱼类的高度地方特有性之外，即使在同一条河流内，不同的急流也被不同的谱系占据。因此，占据不同急流的喜流物种和群落是不可互换的，在提出水电项目的缓解/补偿措施以及保护规划时，必须考虑到这一点。
