温度对高密度循环海水养殖大菱鲆摄食、生长及消化酶的影响

Effects of temperature on feed intake,growth and digestive enzyme activity of turbot Scophthatmus maximus L. in high stocking density of closed recirculation aquaculture system

中文关键词: 温度  摄食  生长  消化酶  封闭循环海水  大菱鲆  高密度

英文关键词: Temperature  Feed intake  Growth  Digestive enzyme  Closed recirculation aquaculture system  Turbot Scophthatmus maximus L  .High stocking density

中文摘要:

      在高密度封闭循环海水养殖条件下(平均密度14.20±0.48 kg/m2)，设置4个温度梯度(14、16、18、21 ℃,分别以A～D组表示), 挑选相近体重(371.68±43.15 g)的大菱鲆进行56 d养殖试验。每个梯度设置3个重复，每个重复30尾鱼。研究高密度封闭循环海水养殖条件下温度对大菱鲆摄食、生长以及消化酶的影响。试验结果表明，温度对大菱鲆摄食、生长以及消化酶活力具有显著影响(P<0.05)。（1）在14～18 ℃范围内，大菱鲆摄食量随温度的增加而增大，但当温度为21 ℃时，该组日均摄食量与其他3组相比出现显著性下降(P<0.05)。A、B、C 3组的日均摄食量分别显著高于D组25.65%、32.26%、45.08%(P<0.05)。（2）大菱鲆生长和存活率随温度的增加表现出先升高后降低的趋势。A、B、C 3组增重率分别比D组提高75.23%、91.05%、121.18%，特定生长率分别提高34.29%、80.00%、102.86%。（3）在14～18 ℃范围内,大菱鲆胃蛋白酶比活力首先随温度增加而增大，当超过18 ℃时，出现显著性下降(P<0.05)。A、B、C 3组的胃蛋白酶比活力分别较D组高116.74%、139.68%、202.64%。各组肠脂肪酶比活力并无显著性差异(P>0.05)。肠淀粉酶比活力则随温度升高而升高,D组分别高于C组10.81%、显著高于B组59.74%(P<0.05)、极显著高于A组115.79%(P<0.01)。本研究表明，高密度封闭循环海水养殖条件下大菱鲆摄食、生长和消化的适宜温度范围为16～18℃，适温范围内的最大摄食率为0.52%～0.55%。 温度对胃蛋白酶比活力及肠道淀粉酶比活力影响显著(P<0.05)。建议在适温范围内(16～18 ℃)，封闭循环水养殖300～600 g体重大菱鲆的最佳投饲率为0.57%～0.61%。

英文摘要:

      Effects of temperature on feed intake, growth and digestive enzyme activity of turbot Scophthatmus maximus L. were investigated in high stocking density of closed recirculation aquaculture system. Fish with a mean initial weight of 371.68 ±43.15 g were reared at four different temperatures (14℃, 16℃, 18℃, and 21℃) for 56 days. Three hundred and sixty fish were randomly allotted in four treatments with three replicates for each treatment in a stocking density of 14.20±0.48 kg/m2. The results indicated: (1)Within the temperature of 14～18℃, the feed intake of turbot increased with the increasing temperature, but when the temperature was 21℃, the average daily feed intake of this group was significantly lower than the other three groups(P<0.05). The average daily feed intake of group A, B, and C were significantly higher than D group by 25.65%, 32.26%, and 45.08% respectively (P<0.05). (2)Growth and survival rate of turbot increased first then decreased with the rising temperature. The weight gain rate of group A, B, and C was higher than group D by 75.23%, 91.05%, and 121.18% respectively, while the specific growth rate was 34.29%, 80.00%, and 102.86% respectively.(3)Pepsin activity of turbot first increased with the increasing temperature(14~18℃)and then significantly decreased when the temperature was 21℃(P<0.05). The pepsin activity of group A, B, and C was higher than group D by 116.74%,139.68%, and 202.64% respectively. There was no significant difference in intestinal lipase activity among four groups(P>0.05), while the intestinal amylase activity increased with the increasing temperature, and group D was higher than group C by 10.81%, significantly higher than group B by 59.74% (P<0.05)and significantly higher than group A by 115.79%(P<0.01). This study showed that the optimum temperature for feed intake, growth and digestive enzyme of turbot in high density closed recirculation aquaculture system was 16~18℃ and the feed intake rate was 0.52%～0.55% at the optimum temperature. Water temperature had significant effect on pepsin activity and intestinal amylase activity(P<0.05). According to this result, we suggest that the proper feeding rate is 0.57%~0.61% in actual farming for turbot with body weight of 300~600 g.