ORCID

Abstract

AimThe 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.LocationWestern Ghats, south-west India.TaxonBarytelphusa cunicularis, Brachyura, Crustacea.MethodsWe 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.ResultsDespite 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 ConclusionsWe 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.

Publication Date

2025-04-26

Publication Title

Journal of Biogeography

ISSN

0305-0270

Keywords

Barytelphusa cunicularis, climate change, critical oxygen tension (P ), genetic structure, hypoxia, metabolic rate (MO ), mtDNA COI, nDNA histone H3, physiological diversity, temperature

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