ANALYSIS AND EVALUATION OF NUTRITIONAL COMPOSITION OF WILD COILIAMYSTUS IN OUJIANG RIVER AT DIFFERENT GONADAL DEVELOPMENT STAGES

This study analyzed the gonadal development and evaluated muscle nutrient composition of wild Coilia mystus from Oujiang River at different gonad development stages (stage Ⅰ, stage Ⅱ, stage Ⅲ, stage Ⅳ and stage Ⅴ). Result revealed that during the development of gonads from stage Ⅰ to stage Ⅴ, the maturity coefficient of female and male wild Coilia mystus from Oujiang River both increased, and the GSI value of phoenix anchovy ovaries was 5 times that of testis. During ovary development stage Ⅰ to Ⅴ, crude fat content decreased significantly, and crude protein and water increased significantly (P<0.05). During sperm development stage Ⅰ to Ⅴ, crude fat content increased significantly, crude protein and moisture decreased significantly (P<0.05), and the ash content first increased and then decreased, indicating that fat is the main energy supply material during ovary development. The amino acid content of female Coilia mystus muscle increased significantly from stage Ⅰ to Ⅴ of ovarian development (P<0.05), and the amino acid content of male Coilia mystus decreased significantly from stage Ⅰ to Ⅴ of testis development (P<0.05). However, the amino acid composition of each reproductive stage was relatively stable. The ratios of total essential amino acids to total amino acids of muscles of female and male fish were (37.88±0.32)%—(41.66±0.44)%, (40.30±0.69)%—(40.94±0.29)%, respectively. According to the standards of amino acid score (AAS) and chemical score (CS), the first restrictive amino acids in the muscles of female and male Coilia mystus at different gonadal development stages are tryptophan, and the second restrictive amino acids are methionine Acid (Met)+Cysine (Cys). During the period of ovary development from Ⅰ to Ⅴ, the most abundant C16﹕0 and C18﹕1 in the reproductive stage showed a downward trend, which may be the main energy-supplying fatty acids. The main fatty acid DHA of polyunsaturated fatty acids showed an upward trend and then a downward trend. During the first to fifth stages of test is development, polyunsaturated fatty acids showed a downward trend. Therefore, in the process of reproduction, the developmental characteristics and changes of muscle nutrition composition of wild Oujiang Coilia mystus are closely related to the reproductive habits of reproductive migration spawning. Mastering the pattern of gonad development is the basis for artificial reproduction of Coilia mystus, and understanding its nutritional components is the prerequisite for scientifically guiding a reasonable diet. These findings provide scientific basis for the further development of artificial breeding practice of Oujiang Coilia mystus.