Higher β- and γ-diversity at species and genetic levels in headwaters than in mid-order streams in Hydropsyche (Trichoptera)

Authors

  • Cesc Múrria,

    Corresponding author
    1. Department of Entomology, Natural History Museum, London, U.K
    2. Department of Life Sciences, Imperial College London, Ascot, U.K
    • Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
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  • Núria Bonada,

    1. Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
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  • Miquel A. Arnedo,

    1. Institut de Recerca de la Biodiversitat & Departament de Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
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  • Narcís Prat,

    1. Grup de Recerca Freshwater Ecology and Management (FEM), Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain
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  • Alfried P. Vogler

    1. Department of Entomology, Natural History Museum, London, U.K
    2. Department of Life Sciences, Imperial College London, Ascot, U.K
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Correspondence: Cesc Múrria, Département de Biologie, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.

E-mail: cmurria@ub.edu

Summary

  1. The influence of local habitat characteristics and landscape barriers on the distribution of species and genetic diversity remains poorly known. We tested for differences in turnover and total diversity in aquatic insect assemblages among headwater and mid-order reaches, two habitats presumably differing in their connectivity between catchments.

  2. The genus Hydropsyche (Trichoptera) includes 17 species in the eastern Iberian Peninsula and northern Morocco. Cytochrome c oxidase subunit I (cox1) gene was sequenced for Hydropsyche assemblages at 38 headwater sites and 12 mid-order sites. Local species and intraspecific genetic diversity and differentiation among populations were measured.

  3. A total of 231 cox1 sequences resulted in 83 unique haplotypes that clustered into 19 genetic species entities. We find that α-diversity did not differ between headwater and mid-order habitats at species and genetic levels, but total species numbers and intraspecific genetic diversity (γ-diversity) were higher for headwater than for mid-order or lowland clades, due to greater turnover among sites (β-diversity).

  4. The study revealed lineage-specific evolutionary responses to different river zones, presumably because of differences in the strength of landscape barriers. The multispecies community genetic approach provides a comprehensive picture of diversity patterns in Hydropsyche, as it links habitat heterogeneity and dispersal limitations to genetic structure and lineage diversification.

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