Estimation of genetic parameters for growth traits of Chinese shrimp Fenneropenaeus chinensis

Twenty-one half-sib families(47 full-sib families)of the Chinese shrimp Fenneropenaeus chinensis were obtained by artificial insemination.Eight growth traits of 1 387 shrimps of these families were measured,including body length,cephalothorax length,cephalothorax width,width of the second and third abdominal segment,height of the second and third abdominal segment,length of the first abdominal segment,length of the last abdominal segment and body weight.The values of heritability were estimated using mixed-animal model in multiple-trait derivative-free restricted maximum likelihood(MTDFREML)software,with average body weight as covariate,and family as a random factor in the statistical model.The heritability estimates for all growth traits were at medium level,ranging from 0.04±0.13~0.20±0.16.The heritability was 0.10±0.06 for total body length,0.07±0.06 for cephalothorax length,0.05±0.04 for cephalothorax width,0.20±0.16 for the width of the second and third abdominal segment,0.04±0.13 for the height of the second and third abdominal segment,0.09±0.09 for the length of the first abdominal segment,0.19±0.15 for the length of the last abdominal segment and 0.14±0.16 for body weight,respectively.Genetic correlations were high between the growth traits.The genetic correlation between cephalothorax width and total body length was the highest(1.0±0.01),and that between the length of the first abdominal segment and the width of the second and third abdominal segment was the lowest(0.82±0.08).The findings in this work suggested that these growth traits were under additive genetic control and are expected to respond to selection.The high and positive genetic correlation between growth traits indicated that selection for high body length levels would result in positive response in other traits.Correlation analysis of genetic parameters could quantify the relationship between growth traits,and facilitate the planning for multi-traits breeding programme.Growth traits of little correlations should be excluded in practice,in order to achieve the best result of selection for the target traits.The results of this study provided theory basis for indirect and early breeding of F.chinensis.