T2T genome assembly of Micropterus salmoides (female and male)

The largemouth bass (Micropterus salmoides, LMB) is a globally significant species in aquaculture and fisheries. Since its introduction to China in 1983, its aquaculture production has surged, reaching 802,486 metric tons in 2022 and ranking seventh among freshwater fish farmed nationally.The species exhibits pronounced sexual dimorphism, with females demonstrating higher aquaculture value. However, the sex determination mechanisms in this species remain unclear. In this study, we present the first telomere-to-telomere (T2T) genome assemblies for both sexes of LMB, achieving near-completeness as the first such resource within the order Perciformes. Leveraging these assemblies, we identified a 90-kb Y-specific structural variation (SV)-enriched region (SVER-Y) on chromosome 10, characterized by male-specific SVs and significant enrichment of transposable elements (TEs). These findings establish a critical foundation for advancing population genetics, sex determination mechanism studies, and molecular marker development in LMB.