Genetic structure and evolutionary history of the tiger shrimp Penaeus monodon across its wild and introduced ranges

Abstract Understanding the impacts of domestication and aquaculture on native populations is a key issue in conservation and evolutionary biology, particularly in the context of marine invasions. While aquaculture has greatly expanded the global distribution of species, its influence on genetic diversity and population structure remains poorly understood. This study examines the tiger shrimp Penaeus monodon , native to the Indo-Pacific and introduced across the Atlantic for aquaculture since the 1970s. Nevertheless, the evolutionary consequences of secondary contact between native and introduced populations remain poorly resolved. Using mitochondrial DNA and microsatellite markers, we reconstructed the invasion process and explored patterns of genetic diversity, phylogeographic relationships, and demographic changes across native, invasive, and aquaculture populations. Samples were collected from Indo-Pacific populations, six Atlantic countries (four western and two eastern), and aquaculture facilities to assess the role of human-mediated dispersal in shaping genetic connectivity. Results revealed high genetic variability across all sites and three genetic clusters, indicating complex historical and recent dispersal events. Significant genetic divergence was detected among P. monodon lineages, alongside demographic expansion in aquaculture populations. Conversely, both native and invasive populations exhibited signals of genetic bottlenecks. These findings suggest that aquaculture systems may mitigate founder effects and act as reservoirs of genetic diversity, enhancing invasion potential. Our results underscore the dual role of aquaculture as both a driver of biological invasions and a modifier of evolutionary trajectories, highlighting the need for greater understanding of domestication processes in shaping the genetic landscape of marine species.