Anatomy of the heart and coronary blood supply of the white-eared opossum (Didelphis albiventris)

ABSTRACT Although the white-eared opossum is frequently observed in both rural and urban environments, there is little anatomical knowledge about this marsupial species. To our knowledge, there are no descriptions of its heart anatomy. Thus, the aim of this study was to describe the anatomy of the heart and its coronary blood supply in the white-eared opossums. Eight adult white-eared opossums (Didelphis albiventris) were used. Heart anatomical features and the coronary blood supply were examined using gross dissection and latex cast preparations. The heart of the white-eared opossum was located between the second and fifth intercostal spaces. Pectinate muscles were observed inside the atria, while papillary muscles and chordae tendineae inside the ventricles. Left and right coronary arteries emerged from the ascending aorta. The main branches of the left coronary artery were the paraconal interventricular and circumflex branches, whereas the subsinuous interventricular branch was the main branch of the right coronary artery. The findings of this study suggest that it is likely that the white-eared opossum presents a balanced pattern without dominance by the coronary arteries, since each coronary artery has an interventricular branch. Furthermore, cardiac morphology in white-eared opossums did not differ from that reported for other domestic and wild mammals.