Comparison of Growth Performance, Serum Biochemical Indices, Immune Responses, and Muscle Development in Larimichthys crocea With Different Strains

As a member of the order Perciformes, family Sciaenidae, and genus Larimichthys , the large yellow croaker ( Larimichthys crocea ) is characterized by tender, delicious, and nutritious flesh. This experiment was designed to investigate the differences in growth performance, serum biochemical indices, and muscle quality among different strains of large yellow croakers (initial average weight: 5.11 ± 0.11 g; final average weight: 383.50 ± 11.50 g). Individuals were randomly selected from each strain of large yellow croakers, including the Wenzhou common strain (LYC1), Dai‐qu population (LYC2), Fufa 1 (LYC3), and Ningde common strains 1 (LYC4) and 2 (LYC5), for the analysis of population genetic diversity. The results showed that the weight gain rate and specific growth rate exhibited no significant differences among the LYC1, LYC4, and LYC5 groups but were significantly lower than those of the remaining two groups ( p < 0.05). The muscle of the LYC3 group was found to have the highest crude protein content, coupled with the lowest crude lipid and moisture contents in muscle tissue. The relaxation time of noneasily flowable water in the muscle was the shortest in the LYC3 group. Serum levels of alanine aminotransferase, aspartate transaminase, and malondialdehyde were significantly lower in the LYC3 group than those in the other four groups ( p < 0.05). Serum activities of superoxide dismutase, catalase, alkaline phosphatases, and acid phosphatases were significantly higher in the LYC2 and LYC3 groups than those in the LYC1, LYC4, and LYC5 groups ( p < 0.05). Muscle contents of total volatile base nitrogen and thiobarbituric acid reactive substances were significantly lower in the LYC3 group than those in the LYC1 and LYC5 groups ( p < 0.05). The muscle cell diameter of the LYC3 group was significantly smaller than those of the other four groups, whereas the muscle cell density was significantly higher than those of the other four groups. The muscle of large yellow croakers in the LYC3 group presented optimal hardness, cohesiveness, springiness, gumminess, and chewiness. Muscle lipase and amylase activities were significantly higher in the LYC3 group than those in the other four groups, while muscle protease activity was remarkably lower in the LYC3 group than those in the LYC1, LYC2, LYC4, and LYC5 groups. Muscle levels of alanine aminotransferase and malondialdehyde were significantly lower in the LYC3 group than in the other experimental groups ( p < 0.05). Muscle activities of superoxide dismutase, catalase, and acid phosphatase were significantly higher in the LYC3 group than those in the other four groups ( p < 0.05). The mRNA expressions of muscle superoxide dismutase, catalase, and glutathione reductase were significantly upregulated in the LYC3 group compared with the other four groups ( p < 0.05). The mRNA expressions of muscle myogenic factor 4, myogenic factor 5, myoblast determination protein, and myogenin were significantly higher in the LYC2 and LYC3 groups than those in the LYC1, LYC4, and LYC5 groups, while the mRNA expression of myostatin was significantly lower in the LYC2 and LYC3 groups than those of the other three groups ( p < 0.05). In conclusion, the LYC3 group strain of large yellow croakers displays optimal growth performance and muscle quality. Meanwhile, this study provides a reference for exploring the molecular mechanisms underlying the differences in muscle quality among different strains of large yellow croakers in further research.