中国鲎消化道发育组织学观察

Histological observations on the development of digestive tract in Tachypleus tridentatus

采用石蜡连续切片和H-E染色技术,对15日龄~2龄及成年中国鲎(Tachypleus tridentatus)的消化道进行组织学观察。结果显示,15日龄,消化道组织结构尚未出现明显分化,为一管道状结构,此时黏膜上皮清晰可见,且出现黏膜皱褶;26日龄,食道和胃的黏膜上皮边缘层均出现深色条带,肌纤维增多;30日龄,中肠和直肠的黏膜上皮顶部出现纹状缘,肌层纤维束增厚;60日龄,食道和胃的黏膜上皮边缘层的深色条带发育为纹状缘;70日龄,中肠和直肠黏膜皱褶增高,数量增加,纹状缘着色加深;2龄(约90日龄),消化道由黏膜层、黏膜下层、肌肉层及浆膜组成,食道、胃、中肠、直肠的组织结构可明显区分;成年个体,其消化道黏膜层、黏膜下层、肌肉层及浆膜各层组织均较前期明显增厚,为完整的消化道组织结构。结果表明,中国鲎消化道的组织结构在2龄时基本发育形成,与其2龄开口摄食的生活习性相适应。研究丰富了中国鲎的基础生物学内容,可为今后开展消化生理、资源开发利用以及保护生物学等研究提供理论参考。

In this study,paraffin sections and H-E staining were used to study the individual development of alimentary canal of T.tridentatus at 15 days old,30 days old,60 days old,the second instar and adult.Results showed that the structure of digestive tract of T.tridentatus at 15 days old was not clearly distinguished.The esophagus,stomach,midgut and rectum were similar in structure.Only mucous membrane was clear,and mucous folds were relatively short.When T.tridentatus was 30 days old,the mucous epithelium of esophagus and stomach showed dark bands,the muscle fibers of esophagus extended in a ring,and the muscle bundles of stomach were thickened.The mucous epithelium of the middle intestine and rectum had a striate border at the top,and the muscular fiber bundles were thickened.When T.tridentatus was 60 days old,the dark bands at the top of the mucosa epithelium of the esophagus and stomach developed into striate margins,with increased esophageal muscle fibers and thickened gastric myofilament bundles.The mucosa fold of the midgut and rectum increased in height and number,and the pigmentation of the striate border deepened.The digestive tract of the second instar T.tridentatus was composed of mucous layer,submucous,muscle layer and serosal layer,and the tissue structure was basically well-developed.With the gradual improvement of tissue structure,the number of folds of esophagus and gastric mucosa increased significantly to 9-15,and the striate border at the top of the mucosal epithelium developed into chitin layer.The number of folds in the mucosa of the middle intestine and rectum increased rapidly to 10-12,and the epithelial striatum of the mucosa of the middle intestine thickened,with little tin layer,and the epithelial striatum of the rectum developed into chitin layer.The structure of digestive tract of adult T.tridentatus was complete,and the mucous layer,submucous layer,muscle layer and serous membrane of digestive tract were obviously thicker than that of early stage.Results showed that the tissue structure of the alimentary canal of T.tridentatus was basically developed at the second instar,and the tissue structure of each layer was thickened with age,which was suitable for its living habit.