Abstract

The caudal aspect of the cranial dorsal fin is a useful blood collection site in many shark species, however, there is scant literature available that provides anatomical detail of the vasculature in this area. The purpose of this study was to delineate the vasculature associated with the cranial dorsal fin in the smooth dogfish and to determine the direction of blood flow. A radio-opaque gel was injected into the vessels of several dead animals. After the gel had solidified the specimens were radiographed and then dissected. Sections of tissue were placed in 10% buffered formalin and evaluated histologically. Vessels were confirmed to be venous. To determine the direction of blood flow, a series of radiographs were taken after injecting contrast media (Omnipaque®) into the dorsal fin vasculature of small, anesthetized brown sharks. Blood flow was conveyed to the posterior cardinal vein, a major vessel that lies adjacent to the aorta in the dorsal aspect of the body cavity and leads to the posterior cardinal venous sinus that drains into the heart. This study suggests that apart from being a convenient site for the collection of blood, these vessels also provide the clinician with a safe, minimally invasive, and effective route for the delivery of intravenous drugs and fluids.