The absorptive surface area of the small intestine of Pteropus poliocephalus (Megachiroptera: Pteropodidae): an important factor in rapid food transit?

Abstract

Food transit time is remarkably short in the fruit bat Pteropus poliocephalus. This report details observations on the morphology of the intestinal villi and microvilli, and relates them to the unusual digestive physiology of the species. The tall, broad, flattened, triangular villi provide mucosal surface area to serosal area ratios which are larger than those reported for other mammalian species with a variety of diets. The relatively high density (≤79/μm2) of very tall microvilli (≤5.7 μm) produces an enormous increase in absorptive surface area of intestinal epithelial cells. The large absorptive surface area may be important in maximising the absorption of predominantly fluid digesta to compensate for the short exposure to absorptive cells because of the short food transit time.