Comparative lengths of digestive tracts of seven didelphid marsupials (Mammalia) in relation to diet

The relative proportions of the digestive tract were rarely explored to understand the behaviour and the ecology of neotropical marsupials. In this study, proportions of the digestive tract and diet were compared in seven opossum species. The animals studied were Didelphis albiventris Lund, 1840, D. aurita Wied-Neuwied, 1826, Metachirus nudicaudatus (Desmarest, 1817), Philander frenatus (Olfers, 1818), Lutreolina crassicaudata Desmarest, 1804, Monodelphis sorex (Hensel, 1872) and Caluromys lanatus (Olfers, 1818). Segments of digestive tracts of marsupials were measured and differences were statistically tested by Analysis of Variance and Covariance. Caecum and hard guts were responsible for the main differences among opossums, although all segments differed significantly. Caluromys lanatus was the most specialised species, with a large hard gut and caecum, small stomach and shorter small gut. The large caecum of M. nudicaudatus and the shortest hard gut of M. sorex were also noticed. The arboreal C lanatus has a well different feeding habit and life style regarding other marsupials studied, such as M. sorex and M. nudicaudatus which are terrestrial, corroborating the results reached.