Morpho-Genetic Divergence and Adaptation of Anadromous Hilsa shad (Tenualosa ilisha) Along Their Heterogenic Migratory Habitats

摘要: Migration of an anadromous fish to heterogeneous environment continuously enforces a selective pressure that incorporates wide range life-history strategies by which individuals adapt the prevailing conditions. Therefore, we used landmark-based morphometric truss network method and nextRAD genotyping-based putatively adaptive SNP loci dataset know how Hilsa shad (Tenualosa ilisha) morpho-genetically habitats across their migratory routes investigating 300 individuals, collected from nine strategic sampling sites covering sea, estuary, upstream freshwater rivers. Different multivariate clustering analyses revealed riverine populations were morphometrically wider (broad type) than estuarine marine (slender type). In case population, north-western turbid population (the Padma Jamuna rivers) had body depth north-eastern clear water Meghna river). The linear model spatial further outcomes in complete concordance with results for different populations. GO enrichment analysis 36 genes, are encoded putative loci, supported presence multiple genes involved growth, metabolism, homeostasis osmoregulation related functions. Several non-mutually exclusive hypotheses attributed explain observation continuum differentiation at both phenotypes genotypes: i) genetic variation largely determines discrimination, ii) interactive evolutionary processes salinity gradients predominantly contribute morphogenetic divergence between marine-estuarine populations, iii) levels influence genotypes leading phenotypic plasticity, iv) local environmental heterogeneity may Finally, concluded adaptation, plasticity ecological consequences jointly determine shad. interaction all these forces relative strength environments, however, made it rather challenging most probable pressure, has shaped diverse habitats.