It is hypothesized that despite sharing a similar habitat, the Muong indigenous and Vietnamese wild pigs may reveal different gastric morphology. Due to the protective nature of procuring these pigs, a total of 12 Muong indigenous pigs and nine Vietnamese wild pigs stomach collected post mortem were analysed for selected biometric parameters and histology. The result indicated that the stomach of the Vietnamese wild pig is broader with a bigger capacity and greater proportion of proper gastric glands. Interestingly, the stomach mass correlated well with live body weight in both breeds apart from possessing similar histomorphometry of the gastric gland regions. On the other hand, the thicker (P < 0.05) submucosa in the Vietnamese wild pig is attributed to the presence of numerous loose connective tissues, abundant blood vessels, adipose tissues and nerve plexus. The appearance of lymphoid follicles underneath the tubular gastric glands in the Vietnamese wild pig exceeded that of Muong indigenous pigs. This finding suggested that the difference in feeding behavior as well as immunity. In conclusion, adaptations found in the Vietnamese wild pig indicated that this breed is equipped with a bigger and effectively functional stomach to suit its digestive physiology and immunity in the wild.
This study was conducted to record the histological features of the gastrointestinal tract of wild Indonesian shortfin eel, Anguilla bicolor bicolor (McClelland, 1844), captured in Peninsular Malaysia. The gastrointestinal tract was segmented into the oesophagus, stomach, and intestine. Then, the oesophagus was divided into five (first to fifth), the stomach into two (cardiac and pyloric), and the intestine into four segments (anterior, intermediate, posterior, and rectum) for histological examinations. The stomach had significantly taller villi and thicker inner circular muscles compared to the intestine and oesophagus. The lamina propria was thickest in stomach, significantly when compared with oesophagus, but not with the intestine. However, the intestine showed significantly thicker outer longitudinal muscle while gastric glands were observed only in the stomach. The histological features were closely associated with the functions of the different segments of the gastrointestinal tract. In conclusion, the histological features of the gastrointestinal tract of A. b. bicolor are consistent with the feeding habit of a carnivorous fish.
The cranial chamber (proventriculus) and caudal chamber (ventriculus) of the stomach of the Red jungle fowl (Gallus gallus spadiceus) were examined by means of light microscopy. Both chambers presented folds of the tunica mucosa lined by a simple prismatic epithelium that was positive for neutral mucin. Simple tubular glands occupied the lamina propria of both chambers; in the ventriculus of older birds, they showed a coiled base. These ventricular glands were lined by simple cuboidal cells represented by the chief cells and a few large basal cells. The luminal and tubular koilin rodlets and folds of the ventriculus were positive to periodic acid Schiff (PAS) stain. The proventricular glands were situated between the inner and outer layers of the lamina muscularis mucosae. Cells lining the tubulo-alveolar units of the proventricular glands showed a dentate appearance. Vacuoles were not observed, and the cells were negative for Alcian-PAS stain. The tunica submucosa was very thin in the proventricular wall. In the ventriculus, it was not separated from the lamina propria owing to the absence of any lamina muscularis mucosae. The tunica muscularis of the proventriculus was formed by a thick inner layer of circular smooth muscle fibres and a thin outer layer of longitudinal fibres. In addition to these layers, oblique muscle fibres formed the most internal layer of the tunica muscularis in the ventriculus.
Colobine monkeys have complex, multichambered, foregut-fermenting stomachs with either three ("tripartite") or four ("quadripartite," adding the praesaccus) chambers where a commensal microbiome digests plant cell walls and possibly detoxifies defensive plant chemicals. Although different potential functions for the praesaccus have been suggested, little evidence exists to support any of the proposed functions. To address the issue of the function of the praesaccus, we collated literature data on diet and compared tripartite and quadripartite species. Our results suggest that the praesaccus is an adaptation to a dietary niche with a particularly high reliance on leaves as fallback foods in colobine clades with quadripartite stomachs, and a higher reliance on fruits/seeds as foods at times of high fruit availability in clades with tripartite stomachs. This supports the notion that a large gut capacity is an important characteristic by which folivores survive on a high fiber diet, and that this large gut capacity may not be necessary for some species if there are seasonal peaks in fruit availability.