The spot-fin porcupinefish (Diodon hystrix), also known as spotted porcupinefish, black-spotted porcupinefish or simply porcupinefish, is a member of the family Diodontidae. The spot-fin porcupinefish is a medium sized fish which grows up to 91 cm, but the average size mostly observed is 40 cm. Its body is elongated with a spherical head with big ...