怀头鲇早期发育阶段消化酶及碱性磷酸酶活性变化(英文)

采用动物性饵料和人工饲料培育1～10日龄怀头鲇(Silurus soldatovi)仔稚鱼,分析测定了全鱼酸性、碱性蛋白酶、淀粉酶、脂肪酶以及碱性磷酸酶的活性。结果表明:孵化后3天开口期仔鱼已具有较高的碱性蛋白酶活性,5日龄时碱性蛋白酶比活力达到较高值,8日龄时出现低值,总体变化呈波动上升趋势;酸性蛋白酶活性在1～8日龄处于较低水平,8日龄后开始迅速升高;淀粉酶活性在5日龄左右达到最高值,随后酶活性开始下降至较低水平;脂肪酶活性变化波动较大,表现为双峰型,两个峰值分别出现在3～4日龄和6～8日龄。摄食动物性饵料仔稚鱼消化酶活性和碱性磷酸酶活性均高于摄食人工饲料。在整个早期发育过程中,碱性蛋白酶比酸性蛋白酶活性高,碱性蛋白酶、淀粉酶比活力在约8日龄仔稚鱼转变期明显下降,而酸性蛋白酶活性开始迅速升高,这说明消化酶活性的变化与仔稚鱼发育过程中消化机能转换具有相关性。怀头鲇在10日龄内碱性磷酸酶活性呈上升趋势,表明怀头鲇胃肠道功能的逐步发育完善。

Digestive enzyme and alkaline phosphatase activities during the early stages of Silurus soldatovi development

To provide a theoretical basis to improve the survival and growth rate and optimize diet of sheatfish(Silurus soldatovi),the activities of certain digestive enzymes and alkaline phosphatases were investigated during larval development of one-ten day old individuals.Results indicated that sheatfish larva(～three days after hatching)had high levels of alkaline protease activity,which peaked at five days old and dipped by eight days old,although the trend was generally upward.Acid protease activity at one-eight days old was low,after which it increased rapidly.Amylase activity reached the highest value at five days old,after which it began to decline.Lipase activity fluctuated markedly and showed two peaks at three-four days old and six-eight days old.Larval digestive enzyme activity and alkaline phosphatase activity were higher when fed live food than when fed an artificial diet.Throughout the early development process,alkaline protease activity was higher than acid protease,alkaline protease and amylase specific activity decreased significantly for eight-day-old transition larvae,while acid protease activity increased rapidly.These results indicate that the changes in digestive enzyme activity were relevant to digestive function conversion during fish larvae development.Alkaline phosphatase activity showed an upward trend over the first ten days of life,which indicated that the gastrointestinal function of sheatfish improved gradually.