Histological and histochemical observations in the stomach of the Senegal sole, Solea senegalensis

An histological and histochemical study was conducted on the stomach of adu lt Senegal sole, Solea senegalensis specimens. The stomach was made up of f our distinct layers: mucosa, lamina propria-submucosa-, muscularis and sero sa. Surface epithelial, glandular and rodlet cells were present in the muco sa. Cells of the columnar epithelium contained a basal nucleus. Numerous mi tochondria, granular endoplasmic reticulum and Golgi apparatus consisting o f several parallel cisternae and vesicles were observed in the cytoplasm of these cells. The lysosomes were small, round and dense. The gastric glands were numerous in the pyloric and fundic regions but absent in the cardiac stomach. These glands were formed by two cell-types: light and dark cells. The light cells were characterised by numerous mitochondria, while dark cel ls had slightly fewer mitochondria and a tubulo-vesicular system. Rodlet ce lls similar to those observed in other teleostean fish were present among t he epithelial cells. Although the epithelial cells of the mucosa contained a weak presence of ne utral and acid mucopolysaccharides/mucosubstances, these substances were ab undant in the lamina propria-submucosa. Proteins rich in arginine, lysine, cysteine and cystine were rarely present in the mucosa and lamina propria-s ubmucosa of stomach, while proteins rich in tyrosine were abundant in these layers. Acid phosphatase, and ATP-ase (pH 7.2 and 9.4) activities were det ected in the mucosa and lamina propria-submucosa, Alkaline phosphatase acti vity was not detected.