Genetic diversity in the threatened freshwater mussel Lampsilis powellii

North America is home to the greatest share of the world’s freshwater mussel diversity; however, over 70% of its ~300 species are endangered or threatened. Lampsilis powellii, the Arkansas Fatmucket, is endemic to Arkansas and now restricted to upstream reaches of the Ouachita and Saline rivers, but the species is declining within this small range. Conservation actions such as augmenting or reintroducing populations may be necessary, but they require knowledge of the distribution of genetic variation within and among extant populations. We analyzed population structure between the South Fork Ouachita River and Saline River using a 607 base pair region of the mitochondrial COI gene and 14 microsatellites designed for Lampsilis abrupta. COI sequences showed little variation and the most common haplotype was present in both rivers. Our mtDNA sequences were indistinguishable from those of L. siliquoidea deposited on GenBank, but we were unable to make conclusions about the taxonomic distinc...

北美洲是全球淡水蚌类多样性最丰富的区域，但该区域约300个淡水蚌物种中，逾70%处于濒危或受威胁状态。鲍氏亮蚌（Lampsilis powellii）俗称阿肯色胖篮蚌（Arkansas Fatmucket），为阿肯色州特有物种，目前仅分布于沃希托河（Ouachita River）与萨林河（Saline River）的上游河段，但该物种在这一狭小分布区内仍呈衰退趋势。诸如种群扩增或种群再引入等保护措施或有实施必要，但此类措施需基于对现存种群内部及种群间遗传变异分布格局的认知。本研究依托线粒体COI基因（mitochondrial COI gene）的607碱基对区段，以及为突角亮蚌（Lampsilis abrupta）开发的14个微卫星（microsatellites）分子标记，对沃希托河南支与萨林河的种群结构进行了分析。COI序列的遗传变异水平极低，且最常见的单倍型（haplotype）在两条河流中均有分布。本研究获得的线粒体DNA序列与基因银行（GenBank）中提交的L. siliquoidea序列无显著差异，但我们无法就其分类学差异性得出确切结论。