The development of thyroid gland in five developmental stages of common carp, Cyprinus carpio L. The thyroid originates from the pharyngeal floor as a median ventral keel in late embryos having four pairs of arches. It differentiates into profollicular aggergations and true follicles with flattened walls and empty lumina or with lumina filled with cotton waste-like material in three days-old elvers. Secretion of homogeneous eosinophilic colloid with a limited increase in the height of follicular wall is noted in five days-old elvers. In nine days-old individuals the follicles increase in size due to coallescence. The thyroid gland reaches its maximal activity as judged by its histology in one-two months-old individuals. The gland is of t

This study investigates the stomach morphology and histochemistry of Clarias gariepinus. Grossly, the stomach is a J-shaped organ with three distinct regions: cardiac, fundic, and pyloric. Histologically, its wall comprises four layers: mucosa, submucosa, muscularis externa, and serosa. The mucosa exhibits broad longitudinal folds lined by high columnar cells with basal oval nuclei. These cells contain apical mucosubstances that react positively with Periodic Acid Schiff (PAS) stain and negatively with Alcian Blue (AB). Gastric pits result from mucosal invaginations. Glands are present in the fundic and cardiac regions but absent in the pyloric. Oxynticopeptic cells exclusively line the fundic glands. Enteroendocrine cells are distr

This study investigates the stomach morphology and histochemistry of Clarias gariepinus. Grossly, the stomach is a J-shaped organ with three distinct regions: cardiac, fundic, and pyloric. Histologically, its wall comprises four layers: mucosa, submucosa, muscularis externa, and serosa. The mucosa exhibits broad longitudinal folds lined by high columnar cells with basal oval nuclei. These cells contain apical mucosubstances that react positively with Periodic Acid Schiff (PAS) stain and negatively with Alcian Blue (AB). Gastric pits result from mucosal invaginations. Glands are present in the fundic and cardiac regions but absent in the pyloric. Oxynticopeptic cells exclusively line the fundic glands. Enteroendocrine cells are distr