RESEARCH ARTICLE
Three-Dimensional Morphometrics Reveal Patterns of Unionid Shell Variation Along River Gradients
Irene Sánchez González,
Jamie R. Bucholz,
Garrett W. Hopper,
Jeffrey D. Lozier,
Carla L. Atkinson,
Corresponding Author
Irene Sánchez González
Odum School of Ecology, University of Georgia, Athens, Georgia, USA
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Correspondence:
Irene Sánchez González ([email protected])
Search for more papers by this authorJamie R. Bucholz
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Department of Biological Sciences, Virginia Teach, Blacksburg, Virginia, USA
Search for more papers by this authorGarrett W. Hopper
School of Renewable Natural Resources, Louisiana State University and Agricultural Center, Baton Rouge, Louisiana, USA
Search for more papers by this authorJeffrey D. Lozier
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Search for more papers by this authorCarla L. Atkinson
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Search for more papers by this authorIrene Sánchez González,
Jamie R. Bucholz,
Garrett W. Hopper,
Jeffrey D. Lozier,
Carla L. Atkinson,
Corresponding Author
Irene Sánchez González
Odum School of Ecology, University of Georgia, Athens, Georgia, USA
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Correspondence:
Irene Sánchez González ([email protected])
Search for more papers by this authorJamie R. Bucholz
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Department of Biological Sciences, Virginia Teach, Blacksburg, Virginia, USA
Search for more papers by this authorGarrett W. Hopper
School of Renewable Natural Resources, Louisiana State University and Agricultural Center, Baton Rouge, Louisiana, USA
Search for more papers by this authorJeffrey D. Lozier
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Search for more papers by this authorCarla L. Atkinson
Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
Search for more papers by this authorFirst published: 10 January 2025
Funding: This work was supported by the National Science Foundation (DEB-1831512 and DEB-1942707).
ABSTRACT
Aim
Understanding the extent of morphological variation across diverse habitats and species can provide valuable insights into how organisms respond to environmental gradients. We quantified intraspecific morphological variation of unionid mussels and assessed how it varied in relation to genetic differentiation and environmental characteristics.
Location
Mobile and Tennessee River Basins, Alabama and Tennessee, U.S.A.
Taxon
Unionid mussels.
Methods
We used innovative three-dimensional (3D) scanning techniques and 3D geometric morphometric analyses, genetic data and environmental variables to quantify morphological variation in seven freshwater mussel species populations and its relationship to genetic differentiation and environmental characteristics.
Results
Our findings indicate that shell morphological variation is correlated with environmental variables in four unionid species, and generally not related to genetic differentiation, improving our understanding of the mechanisms behind morphological variation. Three closely related species were more inflated in larger watersheds, while a more distantly related species, A. plicata, was more compressed in larger watersheds. River bankfull width was a significant factor in all models, highlighting the influence of high flow extremes on shell morphological variation.
Main Conclusions
Our findings suggest that environmental factors, particularly characteristics of river flow regimes, are the primary drivers of intraspecific shell morphological variation in unionid mussels, with genetic differentiation playing a less prominent role. Continuing to explore intraspecific trait variation along river gradients will improve our understanding of the ecological implications of shell morphological variation. Assessing the ability of organisms to morphologically adapt to environmental change can help us understand their resilience.
Conflicts of Interest
The authors declare no conflicts of interest.
Open Research
Data Availability Statement
The data sets analysed in this study are available in the Open Science Framework repository https://doi.org/10.17605/OSF.IO/VPXRM. Raw sequence reads are deposited in the SRA (BioProject PRJNA925109).
Supporting Information
| Filename | Description |
|---|---|
| jbi15084-sup-0001-Supinfo.docxWord 2007 document , 1.3 MB |
Data S1. |
Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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