普安银鲫消化系统胚后发育的组织学观察

Histological Studies on Post-embryonic Development for Digestive System of Carassius auratus

为了解普安银鲫消化系统发育的形态学与组织学变化,采用石蜡切片的方法对普安银鲫仔鱼消化系统的胚后发育进行了观察。结果表明:普安银鲫初孵仔鱼的鱼体透明,消化系统尚未形成,依靠吸收腹部卵黄囊内的卵黄来维持生命和器官发育。1日龄仔鱼卵黄囊背侧有1条直管,即为消化道,此时为内源性营养阶段;2日龄仔鱼消化道管腔明显,消化道上皮细胞出现分化,肛门形成,消化道贯通;5日龄仔鱼消化管加粗,肠内有食物残留,消化系统分化明显,并出现明显的食道、肝胰脏,出现杯状细胞,此时仔鱼进入外源性营养阶段;15日龄仔鱼的食道进一步分化,前肠空泡结构出现,杯状细胞丰富,肝细胞索明显;30日龄幼鱼,消化系统组织结构与成鱼相似,能消化和吸收外源营养物质。说明,普安银鲫仔鱼消化系统的发育与食性的变化相适应。

Paraffin sectioning method was adopted to observe the post-embryonic development of digestive system for fish larvae and to study the morphological and histological changes in digestive system development of C.auratus.The results indicated that the newly hatched fish was transparent and the digestive system had not completely developed,therefore the fish larvae maintained the life and developed the organs by utilizing the nutrient of yolk from yolk sac.The digestive tract was an undifferentiated tube at dorsal side of the yolk sac at first day after hatching as endogenous feeding stage.The epithelium of digestive tract was more obvious,the epithelial cell differentiated,the anus formed,and the digestive tract ran through on 2nd day after hatching.The digestive tract thickened,food residues could be seen in the intestine,the digestive system obviously differentiated,with obvious esophagus,hepato-pancreas,and goblet cells appeared,the larva were at the exogenous feeding stage on 5th day after hatching.The esophageal further differentiated,cavity structure occurred in fore-intestine,with abundant goblet cells,and obvious hepatic cords on 15th day after hatching.The digestive system of juvenile was similar to adult,which could digest and uptake exogenous nutrients on 30th day after hatching.The study illustrated that the digestive system development of fish larva of C.auratus was adapted to the feeding habits.