盐度对大口黑鲈幼鱼生长性能、肌肉品质及抗氧化能力的影响

Effects of salinity on growth,flesh quality and antioxidant capacity of juveniles Micropterus salmoides

为探讨盐度对大口黑鲈(Micropterus salmoides)幼鱼生长性能、肌肉品质和抗氧化能力的影响,分别在淡水、3、6、9、12的盐度梯度下养殖体长为(6.24±0.39)cm、体质量为(5.42±0.58)g的大口黑鲈幼鱼49 d,统计其存活、生长及摄食情况,测定各盐度下大口黑鲈幼鱼肌肉组织的营养成分和大口黑鲈幼鱼肝脏、肾脏、鳃组织中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活力。结果显示:(1)各盐度组大口黑鲈幼鱼成活率均为100%;体长、体质量、增长率、特定生长率和摄食率随盐度的升高均表现出逐渐降低的趋势,饵料系数则表现出逐渐升高的趋势。(2)盐度对大口黑鲈幼鱼水分、粗蛋白和灰分的影响不显著;粗脂肪含量差异明显,且盐度越高粗脂肪含量越低。随着盐度的升高,肌肉中各必需氨基酸质量分数、总量、鲜味氨基酸含量及必需氨基酸指数均呈现先增高后降低的趋势。(3)肝脏中SOD活性随盐度的增加先降低后升高,肾脏中SOD活性随盐度的增加先升高后降低;盐度12组幼鱼肝脏中的CAT显著高于其他盐度组,肾脏和鳃组织中CAT活性很低。大口黑鲈在盐度12以下的水环境中可以存活生长,在盐度6以下的环境中不仅能获得较好的经济效益,还能一定程度地改善肌肉的营养价值和风味,具有在盐碱地推广养殖的良好前景。

The fish with average body length of(6.24±0.39)cm and average body weight of(5.42±0.58)g were exposed to different salinity concentration(0,3,6,9 and 12)for 49 days to research the growth characters,flesh quality and antioxidant capacity of juveniles Micropterus salmoides.The survival rate,growth status and feeding condition were recorded.Meanwhile,the nutritional composition in muscle,the superoxide dismutase(SOD)and catalase(CAT)activities in liver,kidney and gill were tested.The parameters of growth characters,flesh quality and antioxidant capacity showed regularity with the salinity increasing.Meanwhile,the body length,body weight,growth rate,specific growth rate,and feeding rate were decreased.However,the feeding coefficient was increased.The moisture,crude protein and ash were not different in these groups.The crude fat were decreased.However,the content of EAA,TAA,DAA and EAAI in muscle were raised first and then reduced.SOD activities in the liver were decreased first and then increased,but SOD activities in the kidney were raised first and then reduced.The CAT activities in the liver of 12 salinity concentration were significantly higher than in other groups.However,CAT activities in the kidney and gill were lower.In conclusion,M.salmoides could grow under 12 salinity,but the nutritional value,flavor,and economic benefits would be better with salinity less than 6ppt.