School of Sciences, Department of Biological Sciences, São Paulo State University (Unesp), São Paulo, Brazil.
Institute of Biosciences, Department of Morphology, São Paulo State University (Unesp), Botucatu, Brazil.
J Fish Biol. 2020 Jan;96(1):251-260. doi: 10.1111/jfb.14217. Epub 2019 Dec 2.
This study describes anatomical, histological and histochemical features of the digestive tract mucosal layer of the matrinxã Brycon amazonicus, an omnivorous freshwater fish endemic from the Amazon basin. This species presents short thick oesophagus with longitudinal folds, that allow the passage of large food items. The mucosa is lined with a stratified secretory epithelium rich in goblet cells that secrete neutral and acid mucins. The two mucin types provide different viscosity in anterior and posterior oesophagus related to the protective and lubricant functions, respectively. The stomach is a highly distensible Y-shaped saccular organ. Here, it is proposed that this anatomical shape plays an essential role in food storage when food availability is abundant. The stomach mucosa is composed of epithelial cells with intense neutral mucin secretion to protects against gastric juice. The intestine is slightly coiled and presents internally a complex pattern of transversal folds that increases the absorption surface and the retention time of food. Goblet cells in the intestine secrete acid and neutral mucins that lubricate the epithelium and aid in the digestive processes. In the rectum, an increase in goblet cells population occurs that may be related to better lubrication.
本研究描述了亚马逊河特产杂食性淡水鱼类大鳞脂鲤（Brycon amazonicus）消化道黏膜层的解剖学、组织学和组织化学特征。这种鱼的短而厚的食道有纵向褶皱，允许大的食物通过。黏膜衬有富含杯状细胞的复层分泌上皮，这些细胞分泌中性和酸性粘蛋白。这两种粘蛋白类型在前、后食道中提供不同的粘性，分别与保护和润滑功能有关。胃是一个高度可伸展的 Y 形囊状器官。在这里，有人提出这种解剖形状在食物丰富时的食物储存中起着重要作用。胃黏膜由上皮细胞组成，这些细胞强烈分泌中性粘蛋白，以防止胃液侵蚀。肠道略微盘绕，内部呈现出复杂的横向褶皱图案，增加了吸收表面和食物停留时间。肠道中的杯状细胞分泌酸性和中性粘蛋白，润滑上皮并有助于消化过程。在直肠中，杯状细胞的数量增加，这可能与更好的润滑有关。
