Histological study on digestive tract of the rainbow trout

Masters Thesis HİSTOLOGİCAL STUDY ON DİGESTİVE TRACT OF THE RAİNBOW TROUT (Oncorhychus mykiss,W.) Sibel ŞİMŞEK Fırat University Graduate School Naturel and Applied Sciences Department of Fish Production and Breeding 1995,Page 41 In this study, histologic structure of the oesophagus, stomach and intestine of 40 Rainbow trout (Oncorhychus mykiss,W.) brought from Fırat University, Fisheries Faculty, Cip Fish Production and Breeding Foundation were exemined using light mikroscope. The oesophagus epithelium of Rainbow trout was very folded and Its mucosa contains gablet cells. It was dermined that the muscularis layer consists of striated muscle fibres on the outer longitudinal layer and the inner circular muscle layer. There is a thin serosa layer on the outer side. The muscosa of cardiac and pyloric ragions of the stomach had folded and columner cells. The small gastric pits and serous cardiac glands were seen in cardiac stomach. Also the long gastric pits in pyloric stomach and pyloric glands were observed only in its some sections, The circular muscle layer of pyloric stomach was thicker than the layer of cardiac stomach. The mucosa of intestine is composed of folded columnar cells and there are many gablet cells among them. The amount of these cells are more in the small intestine than the large intestine. Goblet cells in the oesophagus and intestine were stained blue with Alcian blue and also stained red-pink with P.A.S. As a result goblet cells contain glucosamineglycan. Key Words:Rainbow trout (Oncorhychus mykiss,W.),Digestive track,Histology.