中华绒螯蟹幼体消化系统发育的研究

MORPHOGENESIS OF LARVAL DIGESTIVE SYSTEM IN ERIOCHEIR SINENSIS (CRUSTACEA: DECAPODA)

于1986,1987两年的3—6月,在浙江平湖水产试验场等地采集中华绒螯蟹五期溞状幼体和一期大眼幼体,对其消化系统发育的研究表明:各期幼体消化道平均全长分别为0.912mm,1.332mm,1.628mm,1.998mm,2.331mm和2.664mm;胃在Z_1中呈椭圆形,到Z,方才明显分化成贲门胃和幽门胃两部分;至于贲门胃内的研磨结构和幽门胃内的滤器则要到大眼幼体才完全形成;在各期幼体中,中肠均是消化道最发达的部分,肠壁细胞呈圆柱状;肝胰管和中肠前盲囊在Z_1中出现,而中肠后盲囊却要到Z_2方才形成。

This study provides a detailed account of the morphogenesis of the digestive system of the first-fifth (Ⅰ-Ⅴ) zoeal stages (Z1-Z5) and a megalopal stage (M) in Eriocheir sinensis. The digestive system is divided into three major divisions: foregut, midgut and hindgut. The mean length of larval digestive tract in each stage is respectively 0.912mm, 1.332mm, 1.628mm, 1.998 mm, 2.331mm, and 2.664mm. The stomach is oval in the first zoeal stage (Z1), then, divided into cardiac stomach (including the gastric mill) and pyloric stomach (including the filter) in the third stage (Z3). The most dramatic morphogenetic change is the gastric mill in the cardiac stomach. The series of pads and ridges in the gastric mill are rudiments of the teeth in the second stage stomach (Z1). The lateral teeth appear in the third stage (Z3). The midgut comprises the intestine, a pair of hepatopancrea tubes, a couple of anterior midgut caeca and the posterior midgut caecum. The occurrence of hepatopancrea tubes was clarified especially.