Sinlapachai Senarat, Jes Kettratad, Wannee Jiraungkoorskul, and Niwat Kangwanrangsan

pp. 561 - 567

Abstract

This study was the first attempt on the classification of the gross anatomy with histological structures of the digestive
tract in the Rastrelliger brachysoma. Based on gross anatomical analysis, the digestive tract (65.68±7.06 cm, n = 25) is
distinctly composed of four parts; oesophagus, stomach, pyloric caeca and intestine, respectively. Base on the histological
analysis of the digestive tract, it is composed of four layers: mucosa, submucosa, muscularis and serosa. The epithelial lining
of anterior oesophagus was shown to be a simple squamous epithelium whereas posterior oesophagus, stomach and intestine
were simple columnar epithelium. The surface of this epithelium positively stained with both Periodic Acid Schiff (PAS) and
alcian blue (AB). The posterior oesophagus exclusively showed high longitudinal fold with numerous gastric glands in the
mucosal layer, which is similar to the stomach structure (cariac and pylorus). Numerous pyloric caeca about 220-225 pieces,
were detected between the stomach and intestine regions. Finally, the intestinal coefficient (IC) was 3.69±0.47 cm. The
anterior intestine presented either various longitudinal folds or various goblet cells. The short longitudinal folds of posterior
intestine were in the higher number of goblet cell than the previous part.