Histological and ultrastructural study of the gastric wall of the freshwater bream, <i>Oreochromis mossambicus</i> (Peters) with Reference to ‘Parietal-Like’ cells

Abstract

The stomach wall of the freshwater bream O. mossambicus is described and compared with that of other bony fishes and vertebrates. The histology of the stomach layers and fine structure of the various cell types of O. mossambicus are basically similar to the corresponding cells of other vertebrates although some differences do occur. The mucosa consists of the following, (a) Surface epithelium distinguished by its luminal location and secretory granules, (b) Gastric pit mucous cells identified by their different location, appearance and secretory granules, (c) Gastric gland cells comprising two cell types designated Type I and II. Type I cells, the chief component of the glands, are large cells characterized by tubulovesicles in the apical cytoplasm. Type II cells are identified by the character of their small dense granules in the cytoplasm, (d) Basally granulated cells were identified, (e) A lamina propria and a muscularis mucosae are also present in the mucosa. A submucosal, muscular and serous coat were distinguished and described. Additionally in the submucosa a prominent stratum compactum and stratum granulosum are present.