The distribution of the freshwater crab Fredius reflexifrons (Ortmann, 1897) (Brachyura, Pseudothelphusidae) in an Environmental Protection Area of the Planalto da Ibiapaba, Northeastern Brazil

Abstract Freshwater crabs are important components of aquatic ecosystems; however, their distributions are restricted because of characteristics of their life history, which hinder conservation strategies. Fredius reflexifrons is a widely distributed freshwater crab of the Amazon basin with relictual occurrences in small wetlands on the Planalto da Ibiapaba in Northeastern Brazil. Habitat degradation, destruction of forest patches, channeling of water bodies, and the use of land for legume cropping can seriously impact the species by leading to the extinction of its relic populations, which have limited distributions in the Área de Proteção Ambiental (APA; Environmental Protection Area) Bica do Ipu of the Planalto da Ibiapaba. The objectives of this study were to assess the distribution of F. reflexifrons in APA Bica do Ipu, identify the main impacts from anthropic activities, suggest potential actions to mitigate these impacts, besides providing recommendations for the expansion of the APA. Fredius reflexifrons was recorded in eleven sites in the Planalto da Ibiapaba, of which nine are new records and five are not located within the APA. These findings evidence the need of expanding the APA to encompass the newly known distribution of F. reflexifrons in order to assure its protection.