Balloonfish

Family: Porcupinefishes (Diodontidae)
Size: Up to 50 cm (20 in) | Common: 15 cm
Depth: 2 – 200m (6 – 650ft)
Distribution: Circumtropical (Atlantic, Indian, and Pacific Oceans).

Identification:
The underwater comedian with a flair for drama. Also known as the Long-spine Porcupinefish.

• Appearance: It features a round, pale body covered in large black blotches and spots. A distinct dark brown bar runs vertically through the eye.
• Spines: Unlike the boxfish, its body is covered in long, sharp spines that lay flat against the body when calm.
• Lookalike: It is often confused with the Spot-fin Porcupinefish. The key difference is the fins: the Balloonfish has clear or yellowish fins without spots, whereas the Spot-fin has spotted fins.

Behavior:
A nocturnal hunter with a unique defense.

• Defense: When threatened or startled, it gulps water and inflates like a prickly balloon, erecting its long spines to deter predators.
• Diet: It is a poor swimmer that hunts at night. It uses its powerful beak (fused teeth) to crush hard-shelled invertebrates like sea urchins, hermit crabs, and mollusks.
• In Bahia Solano: They are usually seen solitary over sandy bottoms or hiding in reef crevices during the day.