The Commerson’s dolphin (Cephalorhynchus commersonii) is an odontocete cetacean specie that lies in the waters of the southern hemisphere. With the aim of studying the course and distribution of Cephalorhynchus commersonii’s coronary arteries, an exhaustive heart dissection was performed on one specimen. To the extent of our knowledge, and basing upon an extensive bibliographic research on the commersonii species, this is the first reported description of a Commerson’s dolphin heart anatomy. Despite the fact that the analysis of a unique specimen does not allow to establish final conclusions, comparisons reveal broad similarities between Cephalorhynchus commersonii’s coronary distribution and previous anatomical studies describing the heart of various marine diving mammals and the human fetus circulation. Diving mammals have developed an anastomotic system along evolution, in order to adjust their bodies to diving imposed conditions, and minimize the oxygen demand of the heart muscle. The present work begins with the identification of the patterns and similarities between Commerson’s dolphin heart anatomy when compared to other odontecete species, to continue with an exhaustive description of the Commerson’s dolphin coronary anatomy.
KEY WORDS: Commerson’s dolphin; Cephalorhynchus commersonii; Delphinidae; Coronary arteries; Heart; Anatomy; Sea mammals.