Anatomy and adrenergic pharmacology of the coronary vascular bed of Pacific blue marlin (Makaira nigricans)

Coronary blood supply to the heart of Pacific blue marlin (Makaira nigricans) is derived principally from efferent branchial arteries of the third gill arch via the hypobranchial arteries. A single coronary artery courses caudally from the hypobranchial arteries along the dorsal aspect of the bulbus arteriosus to the ventricle wall in which it branches extensively. Arterial branches invest the compact myocardial shell, trabeculated myocardium, and the atrium. In common with coronary vascular beds of higher vertebrates, marlin coronary vascular beds contained α-constrictor adrenoceptors and β-dilator adrenoceptors.