Mitochondrial diversity and demographic history of Arctica islandica (Bivalvia: Venerida) in the German waters of the Baltic Sea
Year: 2026
Type: article
Abstract: The semi-enclosed Baltic Sea is a comparatively young brackish ecosystem characterised by strong environmental gradients that can shape genetic diversity and demographic history in marine species. The amphi-Atlantic bivalve Arctica islandica (Linnaeus 1767) inhabits the southwestern Baltic Sea, where populations experience environmental conditions distinct from fully marine habitats. We analysed mitochondrial cytochrome c oxidase subunit I (COI) and cytochrome b (CytB) sequences to assess mitochondrial diversity and infer historical demographic patterns of A. islandica in the German waters of the Baltic Sea. Mitochondrial diversity was high, with widespread haplotype sharing among sampling regions and no evidence of regional structuring. Analyses of molecular variance and pairwise differentiation showed that most variation occurred within rather than among regions. Demographic analyses supported a history of population expansion, while comparison with previously published CytB haplotypes indicated that Baltic Sea specimens belong to widespread mitochondrial lineages distributed across the species’ range. Overall, the mitochondrial data indicate that A. islandica populations in the German waters of the Baltic Sea retain substantial shared mitochondrial diversity despite inhabiting environmentally distinct brackish habitats. These patterns are consistent with postglacial colonisation and a shared demographic history and provide a baseline for future genome-wide studies of population connectivity and adaptive variation.
Source: Scientific Reports
Language: English
Subfield: Genetics
Domain: Life Sciences
SDG: Life below water
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7212278822