Population Genetics of Bivalve Mollusks

Population genetics of bivalve mollusks investigates how genetic variation is distributed within and among populations of clams, oysters and mussels, integrating principles of molecular ecology, evolutionary biology and oceanography. High fecundity and planktonic larval stages frequently result in widespread gene flow, yet physical barriers, ocean currents and anthropogenic activities may structure genetic diversity over multiple spatial scales. Molecular markers such as microsatellites, single nucleotide polymorphisms and mitochondrial sequences have illuminated patterns of connectivity, effective population size and local adaptation. Grasping these processes is crucial for sustainable fisheries, aquaculture breeding programmes and conservation of endangered or commercially important species. Research has revealed that aquaculture practices, translocations and invasive introductions can erode genetic variation, incur inbreeding depression or generate admixture zones, with direct consequences for disease resistance, productivity and ecosystem health. Recent investigations combine high-throughput sequencing with classical population genetic models to forecast responses to climate change, delineate management units and guide restoration efforts across global coastlines.

Research from Nature Portfolio

Recent studies have applied combined mitochondrial and nuclear markers to disentangle population structure and historical translocations of the Manila clam. Global sampling of mitochondrial DNA and microsatellite loci across Asia, North America and Europe has reconstructed introduction pathways, demonstrating concordance between reported transfer records and present-day genetic clusters. Invasive European populations exhibit reduced allelic richness and significant differentiation relative to source regions, emphasising genetic bottlenecks during colonisation. In East Asia, integrated analyses of cytochrome c oxidase I gene sequences and simple sequence repeat loci revealed three primary lineages corresponding to South China, North China and the Japan–Korea region. Natural geographic barriers such as major river outflows, together with extensive aquaculture seed movements, have shaped regional haplotype distributions. Identification of populations with elevated genetic diversity offers potential sources for germplasm conservation and selective breeding initiatives.

Population Genetics of Bivalve Mollusks publication trend

The graph below shows the total number of articles in population genetics of bivalve mollusks across all publications each year (not limited to Nature Index journals).

Technical terms

Microsatellite markers: Short DNA sequences of repeating motifs used to assess genetic variation due to high mutation rates.

Haplotype: A combination of alleles at adjacent loci on a chromosome that are inherited together.

FST: A statistic measuring genetic differentiation among populations relative to total genetic variance.

Effective population size (Ne): The number of breeding individuals in an idealised population that would show the same amount of genetic drift as the observed population.

Genetic bottleneck: A sharp reduction in population size leading to loss of genetic variation.

References

1. Population Genetics of Manila Clam (Ruditapes philippinarum) in China Inferred from Microsatellite Markers. Biology (2023).
2. Population genetics of the Manila clam (Ruditapes philippinarum) introduced in North America and Europe. Scientific Reports (2017).
3. Population genetics of the Manila clam (Ruditapes philippinarum) in East Asia. Scientific Reports (2020).
4. Genetic and Haplotype Diversity of Manila Clam Ruditapes philippinarum in Different Regions of China Based on Three Molecular Markers. Animals (2023).
5. Genetic variability in Ruditapes decussatus clam combined with Perkinsus infection level to support founder population selection for a breeding program. PeerJ (2020).