Comparison of immune defense and antioxidant capacity between broodstock and hybrid offspring of oriental river shrimp (Macrobrachium nipponense): Response to acute nitrite stress

Nitrite is an environmental pollutant in cultures of Macrobrachium nipponense and may induce oxidative stress and apoptosis. The oriental river prawn is an important economic aquaculture species in China, Japan, and Southeast Asia but is experiencing degradation of germplasm resources. Hybridization is a means of genetic improvement that could help to overcome this serious problem. In this study, the parental population (Dianshan Lake (DS) and Dongting Lake (DT)) and the hybrid population were exposed to 0 and 10 mg/L nitrite for 96 h. The survival rate of the hybrid group was significantly greater than the DS and DT groups (P < 0.05). The numbers of positive cells and apoptosis rates in the parental groups were significantly greater than in the hybrid group after nitrite exposure (P < 0.05). As the nitrite concentration increased, the antioxidant, non-specific immunity enzyme activities and antioxidant, immune-related genes in the hybrid group were significantly higher than in the parental groups (P < 0.05). Our findings suggested that the hybrid population had stronger stress resistance than their parental populations, which also provides a reference for follow-up genetic breeding.