锯缘青蟹幼体消化酶活力昼夜节律的实验研究

Experiment Studies on the Diel Variations of Digestive enzyme Activities in the Larvae of Mud Crab, Scylla serrata (Forskal)

定活体培育条件下 ,锯缘青蟹幼体 [氵蚤状幼体 (Z5)、大眼幼体 (M) ] 4种消化酶 (蛋白酶、α-淀粉酶、纤维素酶和脂肪酶 )比活力的昼夜变化 .结果表明 ,青蟹幼体 4种消化酶活力均表现出昼夜节律 .蜕皮后第 2天的 Z5幼体 ,其 4种消化酶比活力仅表现出一种单相周期型昼夜变化模式 .临变态到 M的 Z5幼体和 M幼体 ,其 4种消化酶活力则表现出 4种不同的昼夜变化模式 .讨论了青蟹幼体消化酶活力昼夜节律可能的调节机制 .初步认为 ,幼体消化酶活力的昼夜节律主要受发育期和蜕皮周期的影响 。

In this paper, studies were carried out on diel variations of four digestive enzyme (protease, αamylase, cellulase and lipase) activities in the larvae of mud crab, Scylla serrata, in artificial rearing. Evidences were obtained for diurnal rhythms of digestive enzyme activities in S. serrata larvae. For Zoea V larvae in the 2nd day after molting, the specific activities of four digestive enzyme showed similar monophasic diurnal rnythms. However, in Zoea V larvae shortly before metamophosis and Megalopa, four digestive enzyme activites showed different diurnal variation patterns. The possible regulatiry mechanisms of diurnal rhythms were discussed. It is suggested that light, developmental stages and stages in molt period of individuals be the main factors affecting diel rhythms of digestive enzyme activities, with hormone as intermediate reagent to directly control the synthesis and secretion of digestive enzymes.