Comparison of growth and survival performance among selected population, imported population and inbreeding population in Litopenaeus vannamei

The present study explored the differences in growth,survival and inbreeding depression among selected population,inbreeding population and imported population.Inbreeding population was constructed by full-sib mating of selected population in Litopenaeus vannamei.A standard procedure was used in family construction.Individuals of three populations were tested in the same environment.The growth experimental results showed that,body weight of selected population was significantly higher than those of inbreeding population and imported population(P<0.05).At day 60,body weight of selected population increased by 7.11% and 20.01%,compared with those of imported population and inbreeding populations.Different growth performance was observed among different families and in different population.The body weight of 6012 was biggest in selected population,AGR and SGR is 0.29 g/d and 31.82% higher than the mean of the families,and 61.11% higher than that of the lowest.And the body weight of family 6008 was biggest in imported population,AGR and SGR is 0.33 g/d and 3.17%/d,which was 65% and 33.19% higher than the mean of the families,and 230% and 128.06% higher than that of the lowest.The survival results indicated that the difference of survival between selected population and imported population was not significant(P>0.05),but that was significant(P<0.05)between selected population and inbreeding population,12.74% higher than inbreeding population.Full-sib matings revealed that the amount of inbreeding depression of body weight were 16.68% and 10.76%,and inbreeding depression of survival were 11.30% and 10.54%,compared with selected population and imported population.The estimated average inbreeding depression coefficient of body weight was -6.60% and -4.30% per 10% increase of inbreeding coefficient.These results suggest that selection works well in the breeding program of Litopenaeus vannamei,and inbreeding especially full-sib matings should be avoided in the future breeding programs.