作 者：
梁志强;李传武;刘明求;卞伟;余长生;杨奠元
关键词：
湘华鲮;消化道;形态学;组织学;碎屑食性
摘 要：
采用活体解剖、测量、HE染色等方法,对10尾体长(28.98±2.69)cm湘华鲮[Sinilabeo decorus tungting(Nichols)]消化系统形态学、组织学特征进行了研究,旨在阐明其消化系统特征,并探讨其食性及消化、吸收机理。结果表明,湘华鲮消化系统具有以下特点:(1)消化系统由消化道与消化腺肝胰脏组成,消化道包括口咽腔、食管和肠3部分,无胃;肠道极长,可分为前肠、中肠和后肠,比肠长21.42±3.51,肠盘旋次数42±5。(2)湘华鲮属于碎屑食性鱼类,其取食方式为刮食。(3)从前肠往后,黏膜皱褶由网状转变为Z形褶,且逐渐变稀疏,至中肠的中后段难于分辨。(4)食道和肠道壁均由黏膜层、黏膜下层、肌肉层和浆膜层4层组成。前肠、中肠、后肠三者相互之间的黏膜下层厚度存在极显著差异(P<0.01),纵肌层的厚度存在显著差异(P<0.05),而在皱褶数量、黏膜皱褶高度、环肌层厚度、浆膜层厚度等方面,前肠、中肠、后肠三者相互之间大部分组织形态指标差异显著。(5)从前咽顶壁开始,经过肠道,至肛门处,湘华鲮消化道各处黏膜中均有黏液细胞的分布,且黏液细胞呈不均匀分布。(6)食管及整个肠道均具有消化吸收功能。湘华鲮消化道利用其罕见的长肠、丰富的黏膜褶皱及黏液细胞来完成对硅藻等低能量食物的充分消化吸收,以与其碎屑食性相适应。
译 名：
Morphological and histological observation of the digestive system in Sinilabeo decorus tungting(Nichols)
作 者：
LIANG Zhiqiang1,LI Chuanwu1,Liu Mingqiu1,BIAN Wei1,YU Changsheng2,YANG Dianyuan2 1.Fisheries Research Institute of Hunan Province,Changsha 410153,China; 2.Animal Husbandry and Aquatic Products Bureau of Huaihua City,Huaihua 418000,China
关键词：
Sinilabeo decorus tungting(Nichols);digestive system;morphology;histology;detritivores
摘 要：
Sinilabeo decorus tungting(Nichols) is indigenous to Hunan province,China.This species is currently listed as endangered however little is known about its biology.To address this,we successfully propagated S.decorus tungting in captivity and used the offspring to document the morphology of the digestive system by light microscopy observation of tissue sections.The digestive system consisted of the digestive tract,which was com-posed of mouth,pharynx,esophagus,and intestine,and digestive gland.The specimens we examined had an infe-rior mouth,no stomach,2 pairs of barbels,5 types of pharyngeal teeth(typically 5.4.2/2.4.5),and 42–55+ 45–66 lateral line scales.The intestine was extremely long and twisted 42±5 times.The ratio of intestine length to body length was 21.42±3.51,and that of hepatopancreas weight to total weight was 1.21±0.15.S.decorus tungting is a detritivore that scratches food with its lip.The walls of the intestine and esophagus consisted of mucosa,submu-cosa,muscular coat,and serosa layers.The mucosal layer of the prepharynx upper plate,esophagus,and intestine was covered with wrinkles.The thickness of each layer differed among the segments of the digestive system.The thickness of the submucosa differed significantly between the foregut,midgut,and hindgut(P<0.01).Similarly,the thickness of the longitudinal muscle differed between the foregut,midgut,and hindgut(P<0.05).The submu-cosa and circular muscle were thicker in the esophagus than in the foregut,midgut,and hindgut.Similarly,the mucosal and submucosal thickness was greater in the plica than in the hindgut.The foregut mucosa had 44±6 wrinkles,and the number of wrinkles decreased from the foregut to the hindgut.The density of mucous cells was highest in the mid-plica mucosa of the esophagus(2 100±576 cells/mm2).The density of mucous cells was higher in the plica mucosa of the prepharynx than in the goblet cells of the intestine,and higher in the foregut than in the hindgut.The density of mucous cells differed between the plica mucosa in different regions of the gut and de-creased from the base to the head of the plica mucosa in the esophagus and hindgut.Similarly,the density of mu-cous cells differed between the plica mucosa of the foregut,midgut,and hindgut.The density in the head of the plica mucosa tended to decrease between the foregut and hindgut.Food was absorbed in both the esophagus and the intestine.The morphology of the gut was consistent with that of other detritivores,being characterized by a long intestine,rich plica mucosa,and high density of mucous cells.
