锯缘青蟹幼体消化系统发育的组织学研究

Histological Study on the Development of Digestive System of Larval Scylla serrata

锯缘青蟹幼体消化道随幼体发育逐渐复杂化．食道壁逐渐增厚，肌肉层越来越发达．贲门胃胃磨的结构组成逐渐完善，以适应不同发育时期对饵料的需要，幽门胃内腺滤器的结构逐渐发育形成，以使其过滤功能逐渐完善：ＺＩ只有腺滤器的雏形，ＺＩＶ－ＺＶ才出现过滤结构，大眼幼体和仔蟹，壶腹内具有由刚毛组成的纵行嵴，发育更加完善．中肠壁上皮细胞的形态特征在幼体不同发育时期存在明显不同．幼体肝胰腺的复杂性逐渐增加．中肠前后盲囊随幼体的发育逐渐形成．

The digestive system of larval Scylla serrata becomes more and more complex following the development of larval stages.The wall of esophagus becomes more thicker and the muscular layer is more developed in the later lasrval stages.The develomental chantes of the structural features of the gastric mill occur as the crab pass through the larval stages.The structure of gland filter in pyloric stomach increase in the complexity during larval life.Only rudiment of gland filteroccurs at the first zoea.The structure of gland filter exhibits filterable during the fourth and the fifth stages of zoea.In the megalopa and the first larval crab,there are longitudinal ridges with stiff setae along the ampillae of the gland filter which develope more completely with the development of larval stges.The morphology of midgut epithelium cells is different at different stages of larval Scylla serrata. The complexity of hepatopncreas increase gradually.The anterior midgut caeca and posterior midgut caecum form during the development of larvae.