Estimationof genetic parameters for juvenile growth performance traits in oliveflounder(Paralichthys olivaceus)

The aim of this study was to evaluate genetic parameters of growth traits for improving selective breeding in olive flounder(Paralichthys olivaceus).A total of 82 full-sib families from 2 year-classes with complete pedigree information were used to estimate heritabilities and genetic/phenotypic correlations for 4 growth performance traits(body weight BW,total length TL,body height BH and condition factor K)based on uni-trait and multi-trait linear mixed models,respectively.Data were analyzed by the restricted maximum likelihood(REML)method.The heritabilities of BW,TL and BH were 0.81,0.70 and 0.61,which are relatively high,however,heritability for K is low(0.11).For all growth traits,the common full-sib effects(c^(2))were at a low to moderate level(0.14–0.20);the maternal effects(m^(2))of the traits(except K)were also detected(0.15–0.19).The phenotypic and genetic correlations among BW,TL and BH were highly positive(0.70–0.91),however,the correlations between K and the other 3 traits was low or negligible(−0.22–0.26).According to our results,these traits(except K)could be selected and enhanced simultaneously.In addition,direct selection based on TL or BH,which is an easily measurable trait,will be more favorable than selection on BW.Moreover,our results indicated that growth parameters estimated in the juvenile stage could be used as a predictor of growth performance at later growth stages.