盐度对大口黑鲈生长、肌肉营养成分及肝脏免疫酶活性的影响

Effects of water salinity on growth performance,muscle nutrient composition and liver antioxidant enzyme capacity in Micropterus salmoides

为研究水体盐度对大口黑鲈生长、肌肉营养成分及免疫酶活性的影响,设置盐度为0‰(S0组,对照组)、3‰(S1组)和9‰(S2组)的人工海水进行养殖试验。试验鱼暂养后称重[(28.46±0.10)g],随机分组,养殖周期为8周,养殖全程投喂商品料,试验结束后测定生长性能、肌肉营养成分及肝脏免疫酶活性,以及干露胁迫存活率。结果表明:与S0组相比,S1组大口黑鲈生长性能无显著差异,但S2组生长性能和存活率显著降低,饲料系数显著升高。S1和S2组大口黑鲈干露胁迫存活率显著提高,其中S2组存活率最高。S1与S0组相比肌肉营养成分无显著差异,S2组水分和灰分含量显著降低,而粗脂肪和部分水解氨基酸含量显著升高。与S0组相比,S1组大口黑鲈肝脏各免疫酶活性均无显著差异,S2组超氧化物歧化酶、过氧化氢酶活性及总抗氧化能力均显著升高,同时过氧化物酶活性显著降低,丙二醛含量显著升高。综合而言,盐度为3‰时不影响大口黑鲈生长性能、肌肉组分及肝脏免疫酶活性,但显著提高鱼体耐干露能力;当盐度升高到9‰时,大口黑鲈肌肉粗脂肪含量显著提高,但肝脏氧化损伤加剧,生长性能和存活率显著降低。

In order to study the effects of water salinity on growth performance,muscle nutrient composition and liver antioxidant capacity in Micropterus salmoides,the following experiment was designed.Three different water salinities,i.e.,0‰(S0,control),3‰(S1)and 9‰(S2)were set to raise M.salmoides with initial weight of(28.46±0.10)g.The fish were fed with commercial feed for 8 weeks before they were sampled for growth performance,muscle composition,and liver antioxidant ability determination.In addition,fish survival rate under desiccation was also tested.The results showed that,fish growth performance was not affected in S1 group compared with the control group.In S2 group,however,both fish growth performance and food conversion rate were significantly down-regulated,and fish survival rate was significantly lower than the control group.Moreover,in both S1 and S2 groups,survival rate after desiccation was significantly higher than the control group.Compared with the S0 group,S1 group showed no significant effects on muscle nutrient composition,while S2 group significantly reduced the content of moisture and ash of whole fish,and significantly increased the content of crude lipid and some amino acid.Similarly,S1 group showed no significant difference in hepatic antioxidant enzyme activity compared with S0 group,but S2 group showed significantly higher total antioxidant capacity and malondialdehyde content in the liver.Taken together,our experiment demonstrated that 3‰salinity had no significant effects on the growth,muscle nutrient composition and hepatic antioxidant ability of M.salmoides,but significantly increased fish survival rate under desiccation.Although 9‰salinity significantly increased muscle lipid content and survival rate under desiccation,it caused significantly negative effect on fish growth performance and liver health.