花尾胡椒鲷仔稚鱼期消化酶活性的变化

本文研究了花尾胡椒鲷仔、鱼发育时期不同日龄的三种消化酶活性的变化。早期仔鱼已具有一定的蛋白酶、淀粉酶和脂肪酶活性，蛋白酶比活力在仔稚鱼转变期和稚鱼向幼鱼转变时明显下降，淀粉酶活笥随日 龄增加呈下降趋势，内源营养向外源营养转换过程中，脂肪酶活笥先升后降，进入于期后比活力迅速再次提升。结果表明，消化酶活笥的变化与他、稚鱼发育过程中开矿变化具相关性。混合营养期结束后。１３日 龄仔鱼的三种酶活性均下降，且

Ontogenetic development of digestive enzyme activities in larval and juvenile Plectorhynchus cinctus

Activities of digestive enzymes protease, amylase and lipase in yellow spotted grunt (Plectorhynchus cinctus) were measured from 6d to 49d. The early stage larvae possessed activated enzyme to digest protein, starch and lipid. Protease activity decreased notably during the first few days after commencement of completely exogenous feeding and the days before the beginning of young stage. Specific activity of amylase trended to decline with age. Lipase showed two peaks of specific activity at 9d and 39d. It is suggested that the activities of the digestive enzyme of larval and juvenile Plectorhinchus cinctus are associated with morphological changes during transition period and the low digestive enzyme activity at 13d and 49d may be the cause of high mortality of the larva and juvenile.