Abstract
Indian major carps (IMCs), including Labeo rohita (rohu), Catla catla (catla), Cirrhinus mrigala (mrigal), and Labeo calbasu, constitute the backbone of freshwater aquaculture and capture fisheries in South Asia. Understanding their population genetic structure is essential for conservation, stock management, and selective breeding programs. This review synthesizes available literature on the population genetics of IMCs, focusing on molecular markers, levels of genetic diversity, population differentiation, and the influence of hatchery practices. Studies using mitochondrial DNA, microsatellites, and genome-wide single nucleotide polymorphisms (SNPs) consistently reveal high within-population genetic variation and low to moderate genetic differentiation among riverine populations. However, emerging genomic evidence suggests subtle but biologically meaningful population structuring linked to river basins and historical connectivity. Hatchery-induced genetic erosion remains a major concern. Integrating population genetics into fisheries management and aquaculture breeding programs is crucial for ensuring the long-term sustainability of IMC resources.