Reassessment of the extinction risk of the Neotropical freshwater crabs of the family Pseudothelphusidae

The Neotropical region is one of the world’s biodiversity hotspots, and its freshwater crabs are notably diverse, and are represented by two families, Pseudothelphusidae and Trichodactylidae. This study focuses on this region’s highly diverse Pseudothelphusidae which includes 48 genera and 289 species. The 2008 IUCN global conservation assessment found 15.5% of the Pseudothelphusidae to be threatened with extinction and projected that in the worst-case scenario (if all of the Data Deficient species turned out to be threatened), the number of threatened species would be significantly higher. In the last decade several new species of pseudothelphusids have been described, and more data on the ecology, distribution, and threats of other species has been collected, which together form the main basis of the reassessment presented here. In the present study, 21.5% of pseudothelphusid species were found to be threatened with extinction due to the effects of deforestation, water pollution, and dam construction. Additionally, this study shows the necessity for further work on the freshwater crabs of the Neotropical region, with a special focus on ecology, as well as the urgent need for the implementation of conservation actions