Rhithropanopeus harrisii are small, estuarine crabs native to the Atlantic and Gulf coasts of North America. They have become an invasive species, establishing populations on the west coast of the United States, Europe, Panama, and Japan. Reproducing populations are also established in freshwater reservoirs in Texas and on the Texas/Oklahoma border. In order to compare levels of genetic diversity within introduced reservoir populations with those of native estuary populations and to determine possible source populations and routes of colonization among Texas reservoir populations, we obtained mitochondrial DNA sequences from reservoirs and several estuaries along the Texas and Louisiana coast. Overall, genetic diversity within reservoirs was lower than within estuaries; however, some reservoirs exhibited relatively high levels of genetic diversity indicating that they were founded by numerous individuals or individuals from divergent source populations. In contrast, two genetically divergent reservoir populations had greatly reduced genetic diversity suggestive of extreme founder effects. All estuary and reservoir haplotypes formed a monophyletic group separate from Atlantic coast haplotypes, thus colonization of Texas reservoirs occurred from the Gulf Coast as expected based on geographic proximity. There was minimal DNA sequence divergence among Gulf Coast and reservoir haplotypes and a lack of phylogeographic structure among estuary populations. However, there was significant population divergence among some estuaries based on haplotype frequencies. Genetic differences among estuaries were subtle in most cases, preventing identification of source populations using mitochondrial DNA sequences.

哈里斯树蛙是原产于北美大西洋和墨西哥湾沿岸的小型河口蟹。它们已成为入侵物种，在美国、欧洲、巴拿马和日本的西海岸建立种群。在德克萨斯州和德克萨斯州/俄克拉荷马州边界的淡水水库中也建立了繁殖种群。为了将引入的水库种群内的遗传多样性水平与当地河口种群的遗传多样性水平进行比较，并确定德克萨斯州水库种群中可能的来源种群和定殖路线，我们从德克萨斯州和路易斯安那州沿岸的水库和几个河口获得了线粒体 DNA 序列。总体而言，水库内遗传多样性低于河口；然而，一些水库表现出相对较高的遗传多样性水平，表明它们是由众多个体或来自不同来源种群的个体建立的。相比之下，两个遗传上不同的水库种群的遗传多样性大大降低，表明极端的奠基者效应。所有河口和水库单倍型形成一个与大西洋沿岸单倍型分离的单系群，因此德克萨斯水库的定植发生在墨西哥湾沿岸，如基于地理邻近性的预期。墨西哥湾沿岸和水库单倍型之间的 DNA 序列差异很小，河口种群之间缺乏系统地理学结构。然而，基于单倍型频率，一些河口之间存在显着的种群差异。在大多数情况下，河口之间的遗传差异是微妙的，