Feeding Habits And Nutritional Quality Analysis And Evaluation Of Seriola Aureovittata

This paper mainly focused on the difference in the conversion rate and fractionation coefficient of carbon stable isotopes in different tissues of yellowtail,and discussed the relative contributions of tissue growth and metabolism to the transformation of carbon stable isotopes in different tissues.According to the fractionation coefficient between the corresponding tissue and bait obtained from the culture conditions,and combined with the carbon and nitrogen isotope values of the corresponding tissues and potential diet organisms of the wild yellow strip,the food source of the wild yellow strip was deduced.The nutrients of the muscle tissue collected from wild yellowtail,industrial cultured yellowtail,and sea cage cultured yellowtail were analyzed and evaluated.The main findings are as follows:（1）the conversion difference and fractionation coefficient of carbon stable isotope in different tissues were investigated in yellow tail Seriola aureovittata with body weight of（34.2±1.8）g fed diets containing detected carbon source by stable isotope technique in a laboratory condition at water temperature of 18.79²2.15℃in order to understand the effects of tissue growth and metabolism on the relative contribution of the carbon stable isotope conversion in different tissues of yellow tail.The results showed that the minimal half-life of carbon stable isotope was observed in liver（3.2 d）,followed by intestine（3.4d）,gill（3.6 d）,heart（5.5 d）,and muscle（6.4 d）,and that the minimal enrichment coefficients of carbon stable isotope in liver and diet（0.15‰）,followed by intestine（0.48‰）,heart（0.98‰）,gill（1.02‰）and muscle（1.08‰）.The higher stable isotope conversion rates in liver and intestine were involved in high metabolic rate（>60%）,thus relatively less contribution to growth.Liver and intestine can reflect the isotope alteration during the assimilation of dietary carbon in short-term feeding,while the muscle reflects the isotope alteration of long-term feeding.The findings improved the biology of yellow tail,and provided information for the stable isotope sample collection at different period,diet enrichment and selection in the aquaculture industry.（2）By detecting theδ¹³C andδ¹⁵N values of the liver,intestine,heart,iliac crest,and muscle tissue of the yellow pheasant broiler fed with fresh octopus muscle for 40 days,the fractionation coefficient of each tissue was obtained,combined with the delta ¹³C and the potential food of the yellow sea bream in Dalian.The value ofδ¹⁵N speculates that the food source of yellow stripe in Dalian sea area.The results showed that the fractionation coefficients ofδ¹³C values in the diets of yellow-breasted barley were as follows:muscle（1.00‰）>gill（0.98‰）>heart（0.95‰）>intestine（0.79‰）>liver（0.37‰）;The fractionation coefficients ofδ15N values in the diets were liver（1.55‰）>intestine（1.49‰）>heart（1.18‰）>gill（0.99‰）>muscle（0.81‰）;δ¹³C and muscle tissue of wild yellowtail.Theδ¹⁵N was 12.87‰and-18.63‰.Combined with previous studies,it was found that the longest period of carbon isotope transformation in the tissues of the yellow-fleshed tick was muscle tissue,which could reflect the long-term feeding characteristics.Theδ¹³C value of the food in the wild yellow bar was estimated to be-19.63‰through the fractionation coefficient ofδ¹³C（1.00‰）in the muscle tissue of the yellowtail.The main food sources of the wild yellow stripe in Dalian sea area are middle-upper fishes,with an average contribution rate of 64.0%.Second,the average contribution rate of echinoderms was 8.6%,the average contribution rate of ground fish was 8.3%,the average contribution rate of middle-lower fish was 7.5%,the average contribution rate of swimming lobsters was 4.9%,and the average contribution rate of crabs was only At 4.0%,the average contribution rate of cephalopods was only 2.8%.（3）Using national standards and other methods,the nutrients in the muscles of the wild yellow-fish trapped in the sea,industrialized yellowtail in the sea,and cultured yellow in the sea cage were analyzed and evaluated.The results showed that the protein content of the muscle tissue of the cultured yellowtail was highest in the factory,and that of the yellowtail cultured in the sea cage was the highest,and the yellow bar was caught in the sea.The average AAS and CS scores of the farmed yellowtail were the highest,which were1.00 and 1.33,respectively.The lowest scores of the AAS and CS were 0.88 and 1.18respectively in the sea cage cultured yellowtail.The highest contents of saturated fatty acids and unsaturated fatty acids in the muscle tissue cultured in sea cage cages were（7.06 g/100 g,14.06 g/100 g）,and the lowest levels in the factory cultured yellowtail were（3.83 g/100g,12.60 g/100 g）.