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

Abstract

Freshwater crabs play a crucial role in aquatic ecosystems by contributing to decomposition of organic matter and facilitating energy flow in food webs. They also serve as sensitive indicators of habitat modification, pollution, and other anthropogenic activities. We assessed the relationship between the integrity of Amazonian stream habitats and the abundance and interspecific competition among species of freshwater crab species in Pará, Brazil. Our findings, based on surveys across 35 streams of varying habitat integrity and employing generalized linear models for data analysis, revealed that the loss of riparian vegetation and increased streambank erosion negatively impacted the abundance of freshwater crabs of the family Trichodactylidae. Interactions between species also influenced the abundance of species of Pseudothelphusidae and Trichodactylidae, where their co-occurrence in the streams was analyzed. Our findings underscore the importance of understanding how environmental changes affect the diversity of freshwater crabs and that such changes can be valuable in identifying and mitigating long-term environmental impacts on streams.