The function of digestive physiology during ontogenetic development is essential to ensure high survival and growth rates. In order to evaluate the digestive physiological capacity of the black Amur bream (Megalobrama terminalis), changes of morphology and digestive enzyme activity (trypsin, lipase, amylase, pepsin, leucine aminopeptidase and alkaline phosphatase) in larvae were examined from hatching to 40 days after hatching (DAH). Results indicated that fluctuation patterns differed between the total and specific activities of the digestive enzymes. The total activities of these six enzymes gradually increased throughout the fish growth. The specific activity of trypsin peaked at 5 DAH and then decreased dramatically, while it increased remarkably again from 8 to 10 DAH and remained stable level after 20 DAH. Pepsin activity was first examined in M. terminalis at 15 DAH and gradually elevated towards the end of the experiment. The specific activity of lipase displayed obvious peaks at 5 and 20 DAH. For the amylase, its specific activity reached plateau at 4 DAH, underwent sharp decrease, and remained stable after 20 DAH. In addition, we found that the specific activity of alkaline phosphatase raised significantly from hatching to 5 DAH, and tended to keep slight fluctuation after 15 DAH. From the above, we concluded that the specific activities of digestive enzymes in the larvae varied constantly from 3 to 20 DAH and turned relatively stable after 20 DAH. The present study provides effective information that is useful to improve the seedling cultivation and the technology for healthy breeding.

中文翻译：

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黑A（Megalobrama terminalis）的消化功能的生长和个体发育。

个体发育过程中消化生理的功能对于确保高存活率和高生长率至关重要。为了评估黑鲷的消化生理能力（Megalobrama terminalis），从孵化到孵化后40天（DAH）检查幼虫的形态和消化酶活性（胰蛋白酶，脂肪酶，淀粉酶，胃蛋白酶，亮氨酸氨基肽酶和碱性磷酸酶）的变化。结果表明，消化酶的总活性和比活性之间的波动模式不同。在鱼类的整个生长过程中，这六种酶的总活性逐渐增加。胰蛋白酶的比活性在5 DAH达到峰值，然后急剧下降，而又从8 DAH显着增加，并在20 DAH后保持稳定。胃蛋白酶的活性首先在末端分枝杆菌中检查在15 DAH时逐渐升高，直到实验结束。脂肪酶的比活在5和20 DAH时显示出明显的峰。对于淀粉酶，其比活性在4 DAH时达到平台，急剧下降，并在20 DAH后保持稳定。此外，我们发现碱性磷酸酶的比活性从孵化到5 DAH显着提高，并且在15 DAH之后趋于保持轻微波动。由上可知，幼虫中消化酶的比活性从3到20 DAH不断变化，在20 DAH后相对稳定。本研究提供了有效的信息，可用于改善幼苗栽培和健康育种技术。