Figures 4-7 from: Okuthe GE, Bhomela B (2020) Morphology, histology and histochemistry of the digestive tract of the Banded tilapia, Tilapia sparrmanii (Perciformes: Cichlidae). Zoologia 37: 1-14. https://doi.org/10.3897/zoologia.37.e51043

Figures 4-7 (4) Photomicrograph of the oesophagus of T. sparrmanii showing distinct layers; mucosa (M), submucosa (SM), muscularis which consisted of inner circular (IC) and outer linear and a serosa. H&E stain. (5) An enlarged transverse section of the area marked by box in Fig. 4, showing the epithelial lining of the oesophagus (EP) with mucus secreting cell (G) and connective tissue core (C). Note the absence of mucus cells in some regions of the epithelium (*). H&E stain. (6) Transverse section of the oesophagus of T. sparrmanii, showing AB (pH 2.5) positive cells (arrows). (7) Transverse section of the oesophagus of T. sparrmanii, showing PAS positive cells. PAS/haematoxylin stain. Scale bars: 4 = 20 µm, 5–7 = 50 µm.