RAY ENCOUNTERS AS A MORTALITY FACTOR IN ATLANTIC BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)

Ray spines were found associated with various tissues on necropsy of seven Atlantic bottlenose dolphins ( Tursiops truncatus ). In at least six cases they were considered a major factor in the death of the animal. Three mature Tursiops had ray spines located in the lung parenchyma. In two other dolphins the ray spine punctured the lateral chest wall without entering the lung tissue. A sixth Tursiops contained a ray spine located in the liver tissue, while a seventh animal had a ray spine lodged in the pancreas. Five of the dolphins were wild individuals and two had been in captivity for more than one year. These findings indicate that beached dolphins and dolphins in captivity with a chronic history of illness should be examined for the presence of ray spines. Caution should be used in maintaining mixed exhibits of dolphins with stingray species.