Population Genetics of the Blood Cockle, Tegillarca granosa (Linnaeus, 1758): A Study of Spatial Genetic Structure Across the Indonesian Archipelago

The blood cockle, Tegillarca granosa, holds significant importance within the Asian shellfish ecosystem, both in terms of economic viability and ecological significance. The investigation focused on examining the genetic diversity, historical biogeography, and population structure of the species in order to enhance our comprehension of its evolutionary history. We selected a total of five sites across the Indonesian Archipelago for sample collection. Sequence variation in a segment of mitochondrial DNA control region was characterized in a sample of 200 individuals. Genetic diversity (h = 0.88–0.96) and nucleotide diversity (π = 0.51–0.98) were found to be high compared to the estimates reported for many other similar shellfish taxa. Nonetheless, analysis of molecular variance revealed significant genetic differentiation, F_ST = 0.5530 (p < 0.0001 after Bonferroni corrections). Furthermore, the pairwise fixation index values exhibited significance across all population locations, indicating a constraint on dispersion potential and gene flow. This pattern presumably indicates restricted dispersion ability, facilitating local adaptation to specific locales, hence enhancing the biological, oceanographic, and geographic influences on genetic structure. The findings presented herein establish a basis for formulating improved conservation strategies for the target species.