Biogeography and Phylogeny of the Freshwater Crabs Based on Molecular and Morphological Evidence

淡水蟹提出了许多有趣的进化和地理学问题。 它们代表了螃蟹中最具物种多样性的群体之一，但我们对其系统学和系统发育关系的了解非常有限。 虽然物种繁多，但它们在形态、对淡水的依赖以及不寻常的生活史上都很相似。 基于一些特征，淡水蟹类一直被认为是单系的。 然而，这一观点受到了挑战，因为它们的地理分布令人感兴趣。 这项研究将进行最全面的系统发育研究的淡水蟹迄今为止，使用形态和分子数据的所有淡水谱系及其推定的海洋亲属。 具体而言，我们建议使用形态和分子线粒体和核DNA数据，以建立独立的淡水和eubrachyuran海洋蟹类的单系性，使用这些结果来测试组的单系性，估计淡水蟹类的起源时间，并评估和修订现有的淡水蟹类的高阶分类。

Freshwater crabs pose a number of interesting evolutionary and biogeographic questions. They represent one of the most speciose groups of crabs, but our understanding of their systematics and phylogenetic relationships is severely limited. Although speciose, they are similar in their morphology, their dependence on freshwater, and their unusual life history. Based on a few characteristics, freshwater crabs have long been assumed to be monophyletic. This view has been challenged, however, in light of their intriguing biogeographical distribution. This study will undertake the most comprehensive phylogenetic study of freshwater crabs to date by using both morphological and molecular data for all freshwater lineages and their putative marine relatives. Specifically, we propose to use morphological and molecular mitochondrial and nuclear DNA data to establish independently phylogenies for both freshwater and eubrachyuran marine crabs, to use these results to test monophyly of the groups, to estimate the time of origin of freshwater crabs, and to evaluate and revise the existing higher order classification of freshwater crabs.