条石鲷早期发育阶段消化系统组织学研究

A study on the histology of digestive system in early life stages of Oplegnathus fasciatus

【目的】研究条石鲷Oplegnathus fasciantus从初孵仔鱼到幼鱼这一发育阶段消化系统的形态学变化和组织结构特征.【方法】利用形态学和连续组织切片技术,对出膜后0-35日龄的条石鲷各期仔、稚、幼鱼的消化系统进行了观察和研究.【结果和结论】在水温24-27℃,盐度29-30,p H 7.4-8.2的条件下,初孵仔鱼（0日龄仔鱼）消化道仅是一条位于卵黄囊后的尚未分化的细管状结构,卵黄囊体积较大,H-E染色呈淡红色.随着条石鲷的生长发育,其消化系统也在逐渐成熟和完善,条石鲷消化系统的发育完善要经过3个阶段,第1阶段是0-3日龄,消化道几乎未分化;第2个阶段为4-18日龄,消化系统初步发育成型,具备了基本的摄食、消化和吸收功能;第3阶段为19-35日龄,形成胃腺和幽门盲囊,消化系统发育完善,具备成鱼的结构。

【Objective】The histology of digestive system in early life stages of Oplegnathus fasciatus was investigated. 【Method】By using continual section cutting technique,morphological changes and histological characters from newly hatched larvae to 35 days after hatching were described. 【Result and conclusion】Under the conditions of water temperature 24- 27 ℃,salinity 29- 30 and p H 7. 4- 8. 2,the digestive tract of newly hatched larvae was only an undifferentiated simple closed tube above the posterior segment of yolk-sac with larger volume and color in reddish by H-E staining. Digestive system of O. fasciatus developed their morphology and function further with growth; it can be divided three stages： digestive tract hardly differentiated at the first stage from 0 to 3 days after hatching. At the second stage from4 to 18 days after hatching,the digestive system was brought to primarily perfect,functioning as feeding,digestion and assimilation. At the third stage from 19- 35 days after hatching,gastric glands and pyloric caeca were formed and development of digestive system became perfect and similar to that of the adult fish.