Comparative Histomorphological and Histochemical Studies on the Oesophagus of Nile Tilapia Oreochromis niloticus and African Catfish Clarias gariepinus

Figure 11

Scanning electron micrographs of esophageal mucosa of African catfish (Clarias gariepinus); (a) prominent longitudinal furrows (G) situated in between the longitudinal primary folds (PF). Note the nearly equal size and heights of the longitudinal primary folds (×50). (b) Stratified epithelial cells (SEC) on the primary mucosal folds forming secondary longitudinal folds. Note the deep furrows (G) between the longitudinal mucosal folds (×200). (c) A close look to the longitudinal furrows (G) showing the presence of mucous (M) on the sides on the longitudinal folds. Note the presence of oval shaped stratified squamous epithelium (×600). (d) Squamous shaped SEC forming the secondary folds (SF) with the presence of mucous globules in between (M). Note the presence of openings of empty mucous cells in between SEC (arrow heads) (×1.000). (e) Oval shaped stratified epithelial cells with wavy microridges (MR) on its surface (×6.500). Note the presence of mucous cell (GC) in between. Scale bars: (a) 500 um; (b) 100 um; (c) 20 um; (d) 10 um; and (e) 2 um.

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