大鳞副泥鳅消化系统胚后发育组织学观察

Histological Observation on the Post-embryonic Development of the Digestive System in Paramisgurnus dabryanus

利用组织学和组织化学的方法,对0~50日龄（Days after hatching,DAH）大鳞副泥鳅（Paramisgurnus dabryanus）消化系统胚后发育进行显微观察和研究。结果显示：大鳞副泥鳅初孵仔鱼口咽腔封闭,消化道为一条封闭的柱形直管;3DAH仔鱼卵黄囊体积明显减小,肠道前端开始膨大;4DAH时,仔鱼开口摄食,口咽腔可见味蕾和杯状细胞,消化道迅速发育,食道结构开始分化为前后两部;5DAH时,卵黄囊基本耗尽,肝脏呈网状结构,肝血窦出现;7DAH时,仔鱼的口咽腔味蕾和粘液细胞大量增加,肝脏出现脂肪空泡;15DAH后,食道前后段结构差异显著,后段呈＂I＂形状;20DAH时,食道粘液细胞丰富,肠道、肝脏和胰脏发育逐渐完成;50DAH幼鱼前肠粘膜褶皱结构复杂,粘液细胞丰富,中肠到后肠毛细血管逐渐丰富,管壁也逐渐变薄,形成明显的消化区与呼吸区。研究认为20DAH后大鳞副泥鳅消化系统逐渐发育完善;10~20DAH为肠道呼吸功能形成期,肠道呼吸功能的形成与之生存在静水低氧环境有关。

Histological and histochemical methods were used to observe the post-embryonic development of digestive system in P.dabryanus from hatching（0day after hatching,DAH）until 50 DAH.The results showed that newly hatched larval buccopharynxgeal cavity was closed and digestive tract was a straight tube.At 3DAH,The anterior part of intestine inflated,size of larval yolk sac decreased significantly.At 4DAH,the mouth opened,taste buds and goblet cells could be found,the digestive tract was developing quickly,the esophagus was divided into two different parts;larval yolk sac was depleted,Liver was reticular structure and hepatic sinusoid appeared at 5DAH.At 7DAH,larval taste buds and mucous cells had a substantial increase in buccopharynxgeal cavity and lipid vacuole appeared in liver.After 15 DAH,the structure of anterior and posterior esophagus had significant differences,posterior esophagus was＂I＂shape.The esophagus had abundant mucous cells at 20 DAH.At the same time,the development of intestines,liver and pancreas gradually completed.At 50 DAH,the anterior intestine had abundant mucous folds and mucous cells,the number of blood capillaries turned more while the wall turned thinner from middle intestine to posterior intestine,formed obvious digest and air-breathing region.The results suggested that,it was a critical period of P.dabryanus development of digestive system from 3DAH to 20 DAH.The digestive system of P.dabryanuturned to be completed at 20DAH;Air-breathing function of the digestive tract formed was from 10 to 20DAH,it formed may be due to hydrostatic hypoxia living environment.It＇s necessary to take appropriate managing measures to improve the survival rate of P.dabryanus larvae and juveniles from 10 to 20DAH.