Habitat integrity and interspecific relationships affect the diversity of freshwater crabs (Decapoda: Brachyura: Pseudothelphusidae, Trichodactylidae) in eastern Amazon streams.

This article examines how habitat integrity influences the abundance and interspecific competition of freshwater crabs from the families Pseudothelphusidae and Trichodactylidae in 35 Amazonian streams in Pará, Brazil. Using generalized linear models and species co-occurrence analyses, the study found that reduced riparian vegetation and increased streambank erosion negatively affected trichodactylid abundance, while pseudothelphusid abundance was not directly linked to habitat integrity but was negatively associated with trichodactylid abundance, suggesting competitive interactions. Species-specific responses were observed, with Dilocarcinus pagei (Trichodactylidae) favoring higher habitat integrity and Sylviocarcinus pictus (Trichodactylidae) showing tolerance to altered conditions. The findings highlight the ecological importance of freshwater crabs as bioindicators for monitoring environmental changes and inform conservation strategies for Amazonian aquatic ecosystems.