Selective breeding could improve the juvenile quality of Chinese mitten crab Eriocheir sinensis

Abstract

Chinese mitten crab Eriocheir sinensis is an important aquaculture species in China, and a selective breeding program has been operated for the economic traits of growth and different maturity time of this species since 2011. This study was aimed to evaluate the juvenile quality of two selected E. sinensis lines (i.e. early-maturing strain: EM, late-maturing strain: LM), pond-reared juveniles without selection (PR) and wild-caught juveniles (WC). The results showed that: (1) Significant growth difference were only observed in females that the SGR of EM juveniles and the survivor of WC juveniles were both significantly higher than the PR, and the intermolt period of WC was significantly lower than the PR. Although EM juveniles had relatively shorter intermolt period and higher WGR than the LM, they both exhibited better growth performance than the PR, in terms of higher WGR and SGR. (2) Hepatopancreatic AKP activities of PR juveniles were significantly lower than other three populations for both genders, and hepatopancreatic MDA content was significantly higher in the WC juveniles. Moreover, hemolymphatic levels of ACP and T-AOC of both EM and LM juveniles were significantly higher than other two populations. (3) The injection of Aeromonas hydrophilia resulted in the highest and lowest cumulative mortalities to the WC and PR juveniles respectively, mortalities of EM and LM juveniles were similar and located between WC and PR juveniles. In conclusion, juvenile quality of EM and LM strains obtained certain promotion after three generations of selection for growth and different maturity time.