Genetic and morphological divergences between wild and captive-bred populations ofSalmo trutta abanticus

Abstract

Salmo trutta abanticus is a non-anadromous trout species native to Lake Abant and Seven Lakes in Turkey. A restocking programme by captive breeding was initiated in 1999 to support S. trutta abanticus population. Reared 2-year-old juveniles from randomly caught wild parental individuals in Maçka breeding farm were introduced into Lake Abant. We aimed to compare genetic and morphological divergences between wild- and captive-bred populations using seven microsatellite loci and geometric morphometric measurements. A significant genetic and morphological divergences were detected between all population in Fst and canonical variate analysis based on geometric morphometric with 10 homolog landmark. Eighty-six microsatellites alleles were recorded across loci. Number of private alleles, observed alleles and observed heterozygosity are statistically significant higher in Maçka captive-bred population than Lake Abant and Seven Lakes populations. Of 42 tests, three departures from Hardy–Weinberg equilibrium were detected in all populations after Bonferroni correction. Two pairs of loci (Ssa85 – Str73 and Str73-Str543) in Maçka, one pairs of loci (Ssa85-Str73) in Abant and two pairs of loci (Ssa85-Str60 and Str73-Str543) in Seven Lakes populations show linkage disequilibrium. Population structure analysed with Structure software showed three genetic groups (∆K = 3) in our studied populations. Relatedness estimates show higher mean relatedness values (r = 0.220 ± 0.230) for Maçka captive-breed population than wild populations of Abant Lake and Seven Lakes (r = 0.140 ± 0.210 and r = 0.170 ± 0.200 respectively).