三种水族馆珍贵鱼类的营养成分分析及脂肪酸营养评价

睛斑鳗狼鱼、巨巴西骨舌鱼和锥齿鲨是水族馆中珍贵的展示鱼类,但是有关这3种鱼类成体的营养生理研究却十分缺乏。本研究对从水族馆获得的成年睛斑鳗狼鱼、巨巴西骨舌鱼和锥齿鲨的肌肉和肝脏组织进行了常规营养成分(水分、灰分、粗蛋白和粗脂肪含量)和脂肪酸组成测定分析,并进一步将3种鱼类所食饵料与其肝脏和肌肉中的脂肪酸相对含量进行了比较。结果显示,在3种鱼中,锥齿鲨肌肉和肝脏中的蛋白质含量最高,分别为26.84%和24.03%;睛斑鳗狼鱼的肌肉和肝脏中的脂肪含量最高,分别为41.96%和32.27%;巨巴西骨舌鱼的肌肉和肝脏中的灰分含量最高,分别为4.95%和5.51%。锥齿鲨肌肉和肝脏中饱和脂肪酸(SFA)含量高于睛斑鳗狼鱼,睛斑鳗狼鱼肌肉和肝脏中单不饱和脂肪酸(MUFA)含量高于巨巴西骨舌鱼和锥齿鲨,巨巴西骨舌鱼肌肉和肝脏中多不饱和脂肪酸(PUFA)含量及其肌肉中UFA/SFA值高于睛斑鳗狼鱼和锥齿鲨。研究表明,锥齿鲨所食饵料与其体内脂肪酸组成最为相似,其肌肉和肝脏与饵料的相关系数分别为0.972和0.861,其次是巨巴西骨舌鱼(0.912和0.846),而睛斑鳗狼鱼肌肉和肝脏中脂肪酸组成与所食饵料的相关系数仅分别为0.760和0.681。从脂肪酸营养的角度分析,在当前水族馆养殖条件下,锥齿鲨饵料较为合适,巨巴西骨舌鱼的饵料中应注意添加EPA和DHA,而睛斑鳗狼鱼饵料中则需提高MUFA比例。本研究首次阐明了3种珍贵的水族馆鱼类成体的营养组成,并为水族馆相应的饲料配制提供了重要的参考依据。

Nutrient analysis and nutritional evaluation of fatty acid composition in three precious aquarium fishes

Anarrhichthys ocellatus, Arapaima gigas and Carcharias taurus are three precious fishes, the adults of which are cultured in some aquariums. However, the studies on the nutrient compositions for the adults of the three fishes are still limited. In this study, we measured the compositions of main nutrients (moisture, ash, crude protein and fat content) and fatty acids in muscle and liver tissues in adult A. ocellatus, A. gigas and C. taurus, and their corresponding feed, which were all collected from the aquarium. Furthermore, the correlation of fatty acid composition between the feed and tissues were calculated. The results showed that, the C. taurus had the highest crude protein content among the three fishes in muscle and liver, which was 26.84% and 24.03% respectively. A. ocellatus had the highest crude fat content among the three fishes in muscle and liver, which was 41.96% and 32.27% respectively. The ash content of muscle and liver in A. gigas was higher than the other two fishes, which was 4.95% and 5.51% respectively. The muscle and liver of C. taurus contained higher saturated fatty acids (SFA) content than the other two fishes, while A. ocellatus had higher monounsaturated fatty acids (MUFA) content than the other two fishes. Besides, A. gigas had higher amount of polyunsaturated fatty acids (PUFA) in muscle and liver and UFA/SFA ratio in muscle than the other two fishes. The correlation index showed that the fatty acids composition in feed and tissues (liver and muscle) obtained the highest similarity in C. Taurus. The correlation coefficient of fatty acid composition between feed and muscle and between feed and liver were 0.972 and 0.861, in C. taurus, respectively, and 0.912 and 0.846 in A. gigas, respectively, and 0.760 and 0.681, in A. ocellatus respectively. These results demonstrate that additional EPA and DHA could be supplemented in the feed of A. gigas, and additional MUFA should be added in the feed of A. ocellatus. For the first time, the present work presents the nutrient composition of the adults of the three precious fish species, and also provides valuable suggestions for the feed formulation in aquariums.