三疣梭子蟹蜕壳后肝胰腺消化酶活力变化特征研究

消化酶是反映机体消化生理状况及对营养物质利用能力的重要指标。本文对三疣梭子蟹蜕壳后不同时间肝胰腺消化酶活力进行了研究,结果显示,蜕壳后肝胰腺中胃蛋白酶、胰蛋白酶和淀粉酶活力在第4~6天达到最高;脂肪酶活力在第6天时达到最高;纤维素酶活力总体较低,在第10~12天达到最高;几丁质酶活力在蜕壳后第4天时酶活力最高。研究表明,三疣梭子蟹蜕壳后,胰蛋白酶和胃蛋白酶活力相对较高,而纤维素酶和淀粉酶活力较低,可能与三疣梭子蟹本身的肉食性特征有关;另外,整个实验期间,三疣梭子蟹肝胰腺脂肪酶活力较低,可能与测定条件有一定的关系。与其他时间点相比,蜕壳后4~6 d(蜕壳周期中间阶段)各种酶活力处于较高水平,表明此阶段对食物的消化能力比其他时间更强,这为养殖过程中饵料的合理投喂提供了参考依据。

The variation of digestive enzyme activity in hepatopancreas of Portunus trituberculatus after molting

Digestive enzymes are important in reflecting the physiological state of digestion and the capacity of nutrition utilization. In the present study, digestive enzymes activity in hepatopancreas of Portunus trituberculatus after molting were studied. The results showed that pepsin, tryptase and amylase were the highest at 4~6 d after molting. Lipase activity reached the highest at 6 d after molting. Cellulase was the highest at 10~12 d after molting, though it maintained at a lower level in all the detected time. Chitinase was the highest at 4 d after molting. After molting, P. trituberculatus had high level of pepsin and tryptase activity, while the activity of cellulase and chitinase were low, which might be due to the characterization that P. trituberculatus mainly lived on animal derived food. The lipase activity in hepatopancreas was low, and it might be result from that the optimal determination condition was not provided. Compared to the other time, activity of all the detected digestive enzyme were high at 6 d after molting, which indicated that the crabs of this stage had higher food digestive capacity than that in other time. This result may help to provide reasonable reference for food providing in aquaculture of crab culture.