Nutrient distribution in different tissues of subadult Dabry's sturgeon, Acipenser dabryanus (Duméril, 1869).

Low fertilization rate and hatchability of cultured Dabry’s sturgeon, Acipenser dabryanus,are bottlenecks to the fish species protection, while adequate nutrients in body of subadult fish are crucial to successful reproduction. The present study was conducted to preliminarily understand the nutritional status of male and female subadults by characterizing the proximate composition, fatty acid and amino acid profiles in muscle, liver and gonad of farmed Dabry’s sturgeon with gonads at stage II through chemical analysis, gas chromatograph and high pressure liquid chromatography. The results showed that lipid content (47.24%) in gonad of females was significantly higher than those in liver (29.26%) and muscle (7.72%), while lipid content (39.43%) in liver of males was significantly higher than those in gonad (18.40%) and muscle (6.68%) (p<0.05). The protein content (5.81%) in gonad of females was significantly lower than those in liver (10.77%) and muscle (22.82), while protein contents in gonad (9.23%) and liver (8.72%) of males were significantly lower than that in muscle (20.83%) (p<0.05). The contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in gonad and muscle were the most abundant n-3 polyunsaturated fatty acids (n-3 PUFAs). The content of arachidonic acid (ARA, 0.65%) in gonad of females was significantly higher (0.33%) than that in gonad of males (p<0.05). The results suggest that lipid and highly unsaturated fatty acids, such as ARA, EPA and DHA are accumulated in the gonads at stage II, which may play pivotal roles in gonad development.