台湾泥鳅消化道的形态及组织学结构特征

Morphological and histological characteristics of digestive tract of Paramisgumus dabryanus ssp.

为了解台湾泥鳅消化道的形态结构特点与其消化吸收功能之间的关系,采用活体解剖、石蜡切片以及AB-PAS染色技术,研究台湾泥鳅消化道的形态、组织学结构及黏液细胞的分布.结果显示:台湾泥鳅消化道由口咽腔(舌)、食道和肠道组成,无胃;食道粗短、肠道直、无盘曲,肠指数0.50±0.04;口咽腔上皮中分布有味蕾及Ⅱ型和Ⅳ型黏液细胞;食道和肠道均由黏膜层、黏膜下层、肌层及浆膜构成;食道肌层发达,黏膜皱襞向腔内突起,被覆复层扁平上皮,大量黏液细胞分布于复层上皮内,以Ⅱ型和Ⅳ型为主,还有少量Ⅲ型黏液细胞;肠道各段均被覆单层柱状上皮,上皮层内分布有3种黏液细胞,同样以Ⅱ型和Ⅳ型为主;肠道黏膜皱襞高度以及肌层厚度从前往后呈现下降趋势.台湾泥鳅消化道各部的形态、组织学结构特征及黏液细胞分布特点与其功能相适应.

The current study was designed to investigate the morphological characteristics and the function of digestive tract in Paramisgumus dabryanus ssp., vivisection, paraffin section and AB-PAS staining methods were used to assess the morphological and histological structure of digestive tract and the distribution of mucous cells. The results show that the digestive tract of P. dabryanus ssp. was composed of oropharyngeal cavity(tongue), esophagus and intestines, and no stomach was found. This species were presented with a stubby esophagus and a straight intestine. The intestinal index was 0.50±0.04. In the taste buds, type Ⅱ and Ⅳ mucous cells were distributed in the epithelium of oropharyngeal cavity. Both esophagus and intestine consist of mucosa,submucosa, muscular layer and serous membrane. Well-developed muscular layer was observed in the esophagus, and the mucosal plica protrudes into the lumen. The esophagus was covered with stratified squamous epithelium. A large number of mucous cells were distributed in the epithelium, which were dominated by type Ⅱ and type Ⅳ mucous cells. A marginal part of type Ⅲ cells were also presented. All segments of the intestinal tract were covered by single columnar epithelium. There were three kinds of mucous cells in the epithelium,which were dominated by type Ⅱ and type Ⅳ mucous cells. From the front of the intestine to the back, the height of mucosal fold and the thickness of muscular layer decreased. In conclusion, the morphological and histological characteristics of the digestive tract and the distribution of mucous cells of P. dabryanus ssp. were consistent with its digestive function.