Growth Performance, Nutritional Quality, and Immune-Related Gene Expression of the Chinese Mitten Crab (Eriocheir sinensis) in Pond Ecosystem as Influenced by Stocking Density

Abstract

This study aimed to evaluate the influence of stocking density on growth performance, nutritional quality, and immune-related gene expression of Eriocheir sinensis and water quality in pond ecosystems. E. sinensis were randomly divided into five density groups (G1: 1.2 inds/m2; G2: 1.5 inds/m2; G3: 1.8 inds/m2; G4: 2.1 inds/m2; G5: 2.4 inds/m2) based on their breeding densities, and three replicates were set up for each density group, for a total of fifteen ponds. After 169 days of breeding, the muscle, hepatopancreatic tissue, and hemolymph of E. sinensis, randomly selected from each group, were collected for analysis. Body weight (BW), carapace length, and carapace width increased with breeding time, and the BW of E. sinensis in G3 was higher than that in the other groups. In the muscle and hepatopancreas, the crude lipid content in the G3 group was higher than that in the other groups (p > 0.05). In the muscle tissue, the contents of total, essential, and delicious amino acids in the G3 group were higher than those in the other groups. The expression levels of immune-related genes in G5 were higher than those in the other groups. The value of pH decreased and NO2-N increased significantly in the G5 group and pH, as a synergetic factor of culture density, affected the growth performance of E. sinensis. In conclusion, stocking density has a certain impact on the growth performance, nutrition quality, and immunity of E. sinensis and water quality in pond ecosystems, and a stocking density of 1.8 inds/m2 can be considered optimal for rearing in pond ecosystems of the Poyang Lake region.