Global Patterns, Drivers and Conservation Gaps of Freshwater Crabs: From Species Richness to Phylogenetic Diversity
Wanna Wu, Bing Wang, Zhaomin Zhu, Ruxiao Wang, Boyang Shi, Zhen Wang, Hongying Sun, Da PanABSTRACT
Aim
Freshwater crabs are ecologically vital benthic macroinvertebrates that sustain freshwater ecosystem functions, yet their limited dispersal and fragmented habitats make them vulnerable to human disturbance. Current conservation assessments for freshwater crabs remain incomplete, as most studies focus on species richness while neglecting phylogenetic diversity and conservation gaps. This study aimed to characterize the spatial patterns of freshwater crab species richness (SR) and phylogenetic diversity (PD), identify their key driving factors, and evaluate existing conservation coverage to identify priority areas for targeted freshwater biodiversity protection.
Location
Global.
Methods
We integrated global occurrence data, phylogenetic sequences, and multi‐dimensional environmental and anthropogenic datasets. The distribution data covered 95.83% of genera and 82.86% of species. Using an ensemble species distribution model, we predicted potential species distributions and mapped global patterns of SR and PD. Spatial generalized linear mixed models were applied to quantify the driving factors. We further identified biodiversity hotspots, evaluated conservation gaps and pinpointed priority areas.
Results
Freshwater crab biodiversity exhibited a clear low‐latitude aggregation pattern, with major SR and PD hotspots concentrated in tropical and subtropical regions. Mountain topography and stable hydrothermal conditions promoted crab diversity, whereas strong precipitation seasonality inhibited species accumulation. Large conservation gaps were identified across core hotspot regions, and current protected areas poorly cover freshwater crab diversity. Moderate spatial optimization of protected areas could greatly enhance conservation coverage under global protection targets.
Main Conclusions
Global freshwater crab biodiversity patterns are shaped by coupled environmental and anthropogenic factors, with SR and PD showing heterogeneous spatial responses. Existing terrestrial‐oriented protected areas cannot effectively conserve freshwater crab biodiversity. Optimizing protected area spatial layout based on both SR and PD delivers more efficient conservation outcomes. This study demonstrates the importance of integrating evolutionary information into freshwater conservation planning and provides spatial priorities for filling global freshwater biodiversity conservation gaps.