Comparative gross morphology of the digestive tract in ten Didelphidae marsupial species

Abstract

Natural diets of Didelphidae species vary in the amounts of invertebrates, fruits and small vertebrates eaten. We investigated the digestive morphology of ten species of didelphid marsupials varying in food habits. The purpose was to describe and to compare the shape and relative size of the digestive tract portions among species studied and relate them to food habits. The form of the gastrointestinal tract in this family is simple, with a unilocular stomach, small intestine, large intestine and caecum. Caluromys philander was the species with highest association between digestive tract measurements and its frugivorous habits. However, although its caecum is morphologically distinct from the other species, the relative length is small when compared to the more faunivorous Metachirus nudicaudatus. Stomach length of Philander frenata is related to a more carnivorous diet, while large intestine length of Didelphis aurita is related to its omnivore diet. The digestive tract measurements of the other species appear to be related with a variable degree of morphological differentiation from a generalized form related to omnivory toward a more carnivorous diet. Great caecum relative size distinguished Metachirus nudicaudatus from the most other species and its relationship with diet is not well understood.