The Macropodid Oesophagus I. Gross Anatomical, Light Microscopic, Scanning and Transmission Electron Microscopic Observations of its Mucosa

Abstract

The results of examinations on the oesophagus of 248 animals of 36 species of macropodid marsupials are presented in this paper. Four distinct morphological types of oesophageal lining are described and the species examined classified accordingly. The oesophagus of Aepyprymnus: Bettongia, Dendrolagus, Hypsiprymnodon, Onychogalea; Petrogale; Peradorcas, Setonix and Thylogale has a smooth lining with small and simple longitudinal folds (type 1). The large kangaroos of the genus Macropus (M. antilopinus. M. bernardus, M. fuliginosus, M. giganteus. M. robustus, and M. rufus) have smooth oesophageal linings with extensively pleated longitudinal folds (type 11). The so-called brush wallabies of the genus Macropus (M. agilis, M. dorsalis, M. eugenii, M. irma; M. parma and M. parryi) and Wallabia bicolor have papillated oesophageal linings (type 111). In the red-necked wallaby M. rufogriseus banksianus and the Bennett's wallaby M. r. rufogriseus the oesophagus proximal to the diaphragm is lined with longitudinal leaf-like, laminar plates. and distal to the diaphragm the lining consists of finger-like papillae (type IV). The morphology of the oesophagus in the various macropodid species is discussed in relation to dietary preferences, habitat. and phylogenetic associations between species.