温度对奥尼罗非鱼仔稚鱼生长、饲料利用和消化酶活力的影响

研究了温度22、25、28、31和34℃下奥尼罗非鱼(Oreochromis niloticus×O.aureus)仔稚鱼生长、饲料利用和消化酶活力。结果表明:1)不同温度对奥尼罗非鱼仔稚鱼生长有显著影响(P<0.05),温度为31℃时,仔稚鱼生长速度和绝对增重率最高,分别为0.08cm/d和0.035g/d;温度为22℃时最低,仅0.06cm/d和0.020g/d。2)饲料系数在28℃时最低,仅1.90;22和34℃时较高,达2.14和2.17,各组差异显著(P<0.05)。3)在仔稚鱼发育和存活率上,当温度在22～34℃时,温度越高,仔稚鱼发育越好;各组仔稚鱼的存活率介于93.7%～94.7%,差异不显著(P>0.05)。4)在消化酶活力上,胃蛋白酶、胰蛋白酶和淀粉酶活力随温度升高而升高,均在34℃时活力最高;脂肪酶活力在31℃时达到最高,22℃时活力最低。

Effect of Temperature on the Growth,Feed Utilization and Digestive Enzymes Activity of Larvae and Juvenile of Hybrid Tilapia

Influences of temperature at respectively 22 ℃,25 ℃,28 ℃,31 ℃ and 34 ℃ on the growth,feed utilization and digestive enzymes of larval and juvenile hybrid tilapia were studied.The results showed,(1) The growth of hybrid tilapia did differ significantly(P<0.05).When temperature was 31 ℃,tilapia growth was the fastest,the growth rate was 0.08 cm/d and the absolute growth rate was 0.035 g/d;At the temperature of 22 ℃,the growth of hybrid tilapia was lower,0.06 cm/d and 0.020 g/d respectively;(2) Feed coefficient was low at the temperature of 28 ℃,only 1.90;At the temperature of 22 ℃ and 34 ℃,feed coefficient was high,2.14 and 2.17 respectively,each group had significant difference(P<0.05);(3) On the development and survival of the larvae and juvenile,hybrid tilapia developed well with environmental temperature increasing;survival was 93.7% ― 94.7%,each group did not differ significantly(P>0.05);(4) On the activity of the digestive enzymes,different temperatures had significant effect on the activity of the digestive enzymes of hybrid tilapia(P<0.05),the activities of pepsin,trypsin and amylase were enhancing with environmental temperature increasing,the activities were the highest at the temperature of 34 ℃;lipase activity was the highest at the temperature of 31 ℃,the lowest at the temperature of 22 ℃.