Abstract: The growth and survival at early stage between inbred lines and hybrid systems were compared between full-sib inbreeding families and hybridization of two full-sib inbreeding in two families, A pedigree (F6)and B (F3), of swimming crabPortunustrituberculatuswith different genetic purification in order to breed new families. There were four test groups, including two inbreeding groups F66(A♀×A♂) and F33(B♀×B♂) and two hybrid groups F63(A♀×B♂ ),and F36(B♀×A♂).In terms of reproductive performance, there were significantly higher fecundity, relative egg carrying production and relative larvae releasing production in the inbreeding groups than those in the hybrid groups, especially the fecundity (P<0.05). Within the inbreeding groups, however, there was higher relative egg carrying production and relative larvae releasing production, without significant difference, indicating that the hybrid group showed no advantage in reproductive performance. The growth and survival of juveniles from stage Ⅱ to stage Ⅴrevealed that the hybrid groups F63and F36had general heterosis of 14.38%-25.05% in body weight, and 5.57%-10.27% in full carapace width, higher than the inbreeding groups of F66and F33. The overall growth rate was ranged as the following: F63>F66>F36>F33. There was higher heterosis in F36group than F66and F63group than F66group. The overall survival heterosis of 22.49%-36.67% was found in the hybrid groups, higher in F63group than in F66group, and higher in F36group than in F66group. The findings indicated that the hybrid groups did not show the heterosis in reproductive performance, instead in growth and survival at the early growth stage, which provides foundation for further breeding of swimming crab.
2014, Vol. 29 
