[Morphology and congenital pathology of the heart of the common seal (Phoca vitulina vitulina) (An informative description) (author's transl)].

The morphology and the congenital pathology of the heart of the common seal (Phoca vitulina vitulina) are described. Particular attention is drawn to the dorso-ventral flattening of the heart and the S-like course of the aortic arch. The following congenital malformations of th heart were discussed: (1) patent ductus arteriosus associated with a patent foramen ovale secundum and malposition of the entrance of the caudal caval vein: (2) aplasia of the origin of the left coronary artery: (3) coarctation of the aorta; (4) myocardial bridging. From this study of the heart of the common seal it is concluded that the resistance of the common seal to physical stress is poor. Survival of this animal in the Waddensea requires a quiet and undisturbed biotope.