Publication details
Epigean gammarids may have survived millions of years of severe climatic fluctuations in high-latitude refugia throughout the Western Carpathians: evidence from the Gammarus fossarum complex
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| Year of publication | 2017 |
| Type | Conference abstract |
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| Description | Freshwater amphipods are an ecologically important component of permanent benthic macrofauna in temperate freshwaters. Due to their poor dispersal abilities and absence of dormant stages, amphipod phylogeographies often reflect old historical processes. This has been recently shown for Tertiary lineages of Gammarus species in southeastern Europe. For Central Europe, much closer to the Pleistocene ice sheets, evidence for glacial survival of epigean macrozoobenthos remains inconclusive. We studied the lineage diversity and distribution of the widely distributed Gammarus fossarum complex in two adjacent biogeographically and geomorphologically distinct Central European regions: the Bohemian Massif and the Western Carpathians, and investigated whether the observed patterns are more likely to stem from ancient, postglacial, or present-day factors. Phylogenetic and phylogeographic analyses revealed eight deeply divergent lineages: two exhibit local signatures of recent demographic expansion and inhabit both regions, the other six are only found in the Western Carpathians and display a relict distributional pattern that does not seem to be constrained by the present boundaries of river catchments or topography. Molecular dating indicates that these lineages probably diverged throughout the Miocene (7 to 18 Ma). The contrasting spatial patterns of diversity observed between the two regions thus probably result from historical factors. Our results suggest that despite the high latitude and proximity to the Pleistocene ice sheets, the Western Carpathians may have functioned as a long term glacial refugium for permanent freshwater fauna, allowing the uninterrupted survival of ancient lineages through millions of years of drastic climatic fluctuations. |