MORPHOLOGY OF THE DIGESTIVE TUBE OF THE PODOCNEMIDIDAE IN THE BRAZILIAN AMAZON

We describe the morphology of the digestive tube of Podocnemis expansa, Podocnemis unifilis, Podocnemis sextuberculata, Podocnemis erythrocephala, and Peltocephalus dumerilianus. The esophagus in these species has two distinct regions: the anterior region has esophageal papillae and the posterior has longitudinal folds. Esophageal glands are absent but goblet cells occur in the mucosa of esophagus. The stomach in P. expansa, P. unifilis, and P. erythrocephala has two regions: the anterior region consists of cardiac and fundic regions and is without glands; the more-posterior pyloric region contains gastric glands that extend into the lamina propria. In P. sextuberculata, the stomach is a J-shape, and in Peltocephalus dumerilianus the stomach is a C-shape with a larger curvature to the left side. The stomachs of these two species have numerous gastric glands in all regions. The small intestine (SI) in all species is a long, coiled tube and has folds and villi that appear different in each region. In P. expansa, P. unifilis, and P. erythrocephala, there is a dilatation in the anterior region of large intestine (LI), followed by a straight and tubular region of smaller diameter. In P. sextuberculata and Peltocephalus dumerilianus, the dilatation is absent and the LI is tubular and of uniform diameter along its entire length. The LI has a larger quantity of goblet cells than the SI. The digestive tube of the turtles in the family Podocnemididae demonstrates differences in the morphology between species, and these differences could be related to the diet of each species.