光唇鱼消化道的形态结构特征

采用解剖及石蜡切片显微技术,观察研究了光唇鱼消化道的形态结构特征。消化道由口咽腔、食道、肠构成。口下位、马蹄形,无颌齿,具咽齿,齿式为4/4。舌较小,前端游离,舌粘膜表层为复层鳞状上皮,有较多的杯状细胞和味蕾。食道及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道内皱襞发达,粘膜层有大量杯状细胞。肠道盘曲,由前、中、后肠组成,肠长/体长为1.84±0.24;前肠管腔较大,中、后肠管腔渐变小;前、中肠皱襞及纹状缘比后肠发达;前肠及后肠杯状细胞较少,中肠杯状细胞较多。光唇鱼消化道的形态结构特征与其食性相适应。

Morphological structure features of the digestive tract in Acrossocheilus fasciatus

The morphological structure characteristics of the digestive tract in Acrossocheilus fasciatus were observed by vivisection and paraffin section. The digestive tract can be divided into oropharyngeal cavity,esophagus and intestine. The horseshoe-shaped mouth, located at the lower position,is composed of pharyngeal teeth with a type of 4 /4. But,there are no jaw teeth in it. The tongue is small with a dissociative front end and its mucosa surface is stratified squamous epithelium which contains and caliciform cells and taste buds. The esophagus and intestine consist of mucous,submucosa,muscularis and adventitia. Well-developed plica is present in the esophagus,of which the mucous epithelium is stratified squamous epithelium including abundant goblet cells. The ratio of intestine length to body length is 1. 84 0. 24. The serpentine intestine is comprised of foregut,midgut and hindgut. The foregut lumen is large, while lumens of the latter two structures become smaller gradually. The mucous epithelium of the intestine is simple columnar epithelium,with microvilli on the free surface arranged into striated border. Plica and striated border on the foregut and midgut are much developed than that of the hindgut. There are more caliciform cells on the mucous of the foregut and hindgut. The morphological structure characteristics of the digestive tract of A. fasciatus adapt to its feeding habits.