The brachyuran crab Pseudothelphusa dugesi, or cangrejito barranqueño, is an endangered species endemic to Cuernavaca, Morelos, in central Mexico. Individuals of P. dugesi inhabit freshwater springs, which are affected by human actions through wastewater drainage, eutrophication, exploitation, and invasive predators such as rainbow trout (Oncorhynchus mykiss). In this study, we evaluated the population density, microhabitat use, and size characteristics of P. dugesi. Sampling was conducted in May, July, and December of 2018 and March of 2019, during the dry and rainy seasons in a natural protected area, the Barranca de Chapultepec. Population density was 0.082 crabs/m², female density was 0.052 crabs/m², and male density was 0.112 crabs/m²; ovigerous females were not observed. Males were more abundant than females; the female: male ratio was 1:2.14. Males and females had similar carapace widths and lengths, left and right chelae lengths, and mass. Individuals of P. dugesi were found mostly under or between rocks and under leaf litter. Individuals were more active at night. An understanding of the biology and population characteristics of P. dugesi will help conservationists to develop protective measures and a conservation strategy for this endangered Mexican freshwater crab species.

中文翻译：

---

墨西哥淡水蟹的一种濒危物种Pseudothelphusa dugesi的种群密度，微生境利用和大小特征（Brachyura：Pseudothelphusidae）

Brachyuran蟹Pseudothelphusa dugesi或cangrejitobarranqueño是墨西哥中部莫雷洛斯州Cuernavaca特有的濒危物种。P. dugesi个体生活在淡水泉水中，这些淡水泉水受到人类活动的影响，包括废水排放，富营养化，开发以及诸如虹鳟鱼（Oncorhynchus mykiss）之类的侵入性掠食者。在这项研究中，我们评估了杜氏疟原虫的种群密度，微生境利用和大小特征。在2018年5月，7月，12月和2019年3月的干燥和雨季期间，在自然保护区Barranca de Chapultepec进行了采样。人口密度为0.082螃蟹/ m ²，雌性密度为0.052螃蟹/ m²，雄密度为0.112只螃蟹/ m ² ; 没有观察到雌雄同体。男性比女性丰富。女性与男性的比例为1：2.14。雄性和雌性的甲壳宽度和长度，左，右的长度和质量相似。个人P. dugesi大多下或岩石之间，并在枯枝落叶中。个体在晚上更加活跃。了解杜氏疟原虫的生物学和种群特征将有助于保护主义者针对这种濒临灭绝的墨西哥淡水蟹物种制定保护措施和保护策略。