Abstract:It has been revealed that wild juvenile Eriocheir sinensis (WC) are advantageous in culture performance compared to pond-reared juvenile crabs (PR), however, their differences in the disease resistance, immunity, and the early culture performance remained unclear. In this study we addressed these questions by conducting the culture experiment, the pathogen challenge test, and the analysis of non-specific immune indices. The early culture performance included the first molt interval, survival rate, and weight gain rate. The mortality during the pathogen challenge test and immune indices of WC and PR populations were also examined. Our results were described as follows: (1) Both male and female WC showed significantly lower first molt interval and weight gain rate (WGR) than PRs, but there was no significant difference in the survival rate and the specific growth rate (SGR) between the two groups (P>0.05). (2) Within 12–96 hours in the pathogen challenge test, the cumulative mortality of WC was lower than that of PR, and after 96 hours the cumulative mortality of WC and PR were 28.3% and 50.0% respectively. (3) In terms of the non-specific immune indices in hepatopancreas, the alkaline phosphatase (ALP) activities of both male and female individuals were significantly lower in the WC population than in the PR population. For males, total antioxidant capacity (T-AOC) and nitric oxide (NO) were higher in WC, and for females, malondialdehyde (MDA) was lower in WC. (4) In terms of the non-specific immune indices in hemolymph, WC had significantly higher NO and lower acid phosphatase (ACP) than PR in both sexes. Moreover, for female, WCs had higher T-AOC, hemocyanin (Hc), and glutathione reductase (GR) than PR, but lower ALP, γ-glutamyl transferase (γ-GT), and glutathione peroxidase (GSH-Px). In conclusion, the pond-reared juveniles showed better culture performance during the early culture stage, while wild juveniles had stronger immune ability and lower mortality than the pond-reared juveniles. Each type of the crab seeds may have advantages in certain aspects, and the mechanisms underlying the differences need to be investigated in future studies.
