@article {157489, title = {Metabolic Diversity of a Widely Distributed Tropical Freshwater Crab Is Not Underpinned by Genetic Differences}, journal = {Journal of Biogeography}, year = {2025}, month = {26 April 2025}, abstract = {

Aim

The aim of this study was to understand the interplay between local and regional factors as drivers of population physiological diversity in a tropical freshwater crab species.

Location

Western Ghats, south-west India.

Taxon

Barytelphusa cunicularis,\ Brachyura, Crustacea.

Methods

We applied an integrative approach combining population genetics and whole animal physiology, using the tropical freshwater crab\ Barytelphusa cunicularis\ as our model species. We tested for effects of population location (e.g., latitude, altitude), season (as a proxy for rainfall and water temperature) and/or warming on indices of whole animal respiratory physiology (metabolic rate, MO2) and hypoxic performance (Pcrit, i.e., the PO2\ at which routine MO2\ can no longer be sustained) in five widely distributed populations of this species. We also generated population genetic data (mtDNA COI and nDNA histone H3 sequences) to determine the extent of any population genetic structuring and/or cryptic species diversity present to verify that we were investigating a single species.

Results

Despite a high level of genetic structuring between the different populations of\ B. cunicularis\ examined, the genetic distances observed were consistent with intra- and not interspecific differences in freshwater crabs. Populations varied in the diversity of the physiological (MO2) responses observed. There were significant effects of season and population on respiration in response to temperature and Pcrit\ in response to acute hypoxia.

Main Conclusions

We conclude that local environmental factors are important in shaping physiological diversity between populations in tropical freshwater species and systems. This highlights the need to include population-level responses in any projections we make on how biodiversity will respond to ongoing and future environmental changes, including those caused by climate change.

}, doi = {https://doi.org/10.1111/jbi.15147}, url = {https://onlinelibrary.wiley.com/doi/10.1111/jbi.15147}, author = {Lucy M. Turner and Christopher J. Thorpe and Michael Collins and Smrithy Raj and Tripti Shukla and John I. Spicer and Mairi E. Knight and Dheeraj Sharma and Krushnamegh Kunte} }