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Description & Behavior

Balloonfishes, Diodon holocanthus (Linnaeus, 1758), aka balloon porcupinefishes, blotched porcupine fishes, blotched porcupines, brown porcupine fishes, fine-spotted porcupinefishes, freckled porcupinefishes, freckled porcupinefishes, hedgehog fishes, long-spine porcupinefishes, longspined porcupinefishes, porcupines, porcupinefishes, spiny balloonfishes, and spiny puffers…, are known for their large eyes, spines and their ability to swell up like a balloon when attacked. This rather comical species reaches between 20-35 cm to a maximum of 50 cm. They have a total of 13-15 dorsal and anal soft rays. Juveniles have spots on their ventral (under) sides, adults have dark blotches and spots on their dorsal (upper) sides. They have 14-16 spines between their snouts and dorsal fins. A large brown bar is found above and below each eye; and a broad transverse brown bar on their occipital region (back of the head).

The body of the balloonfish is covered in long, sharp spines that extend when the fish inflates by taking in water. All members of the Family Diodontidae are capable of inflation, and may also change in color when threatened.

World Range & Habitat