Comparative Histological Architecture of the Glandular Stomach in Sciurus anomalus and Urva auropunctata

The present study aims to elucidate the histological organization of the glandular stomach in two mammalian species exhibiting different feeding habits: (i) an herbivorous rodent, i.e., the Persian squirrel (Sciurus anomalus); and (ii) a carnivorous mammal, i.e., the small Asian mongoose (Urva auropunctata). Histological sections (n = 5) were taken from both groups and stained with hematoxylin and eosin (H&E), Alcian blue-PAS stain, and Masson’s trichrome, then microscopic examination was carried out distinct structural adaptations in the gastric mucosa, submucosa, muscularis, and serosa layers could be observed. The squirrel stomach exhibited a moderately thick mucosal layer with abundant mucus-secreting cells, and chief cells, reflecting its herbivorous diet.In contrast, the stomach of a mongoose had a thickened mucosal layer rich in oxyphilic (parietal) cells and a triple-layered muscularis, adaptations corresponding to its carnivorous diet. Mongoose gastric glands were more organized into tubular shapes, and a unique double-layered muscularis mucosae was also observed. This provides insight into processes underlying metabolic adaptations to dietary specialization in mammals, and evolutionary associations among gut size and efficiency according to feeding ecology