Porcupinefish

The Porcupinefish (Diodon hystrix) is the largest species in the family Diodontidae, capable of reaching an impressive 36 inches in the wild. This massive, globally distributed species is found in tropical and subtropical waters worldwide, making it one of the most widespread porcupinefish. Its body is covered in long, prominent spines that lie flat under normal conditions but erect dramatically when the fish inflates itself as a defense mechanism, creating a nearly impenetrable ball of spikes.

The body coloration consists of a light tan to grayish base covered with small dark spots, with the spots extending onto the fins. Its large, expressive eyes and broad face give it the endearing, almost puppy-like appearance shared by all porcupinefish. The long spines of D. hystrix distinguish it from the shorter-spined Diodon holocanthus, which is more commonly seen in the aquarium trade.

Due to its enormous potential adult size, the Porcupinefish requires an exceptionally large aquarium of at least 300 gallons, making it suitable only for the most dedicated aquarists with the space and resources for such a system. Despite its intimidating size and armament, it is surprisingly peaceful toward fish tankmates. It develops a remarkably interactive personality, recognizing its keeper, begging for food, and even accepting gentle touch. However, it will consume any invertebrate it encounters and produces a massive bioload requiring industrial-strength filtration. This species is strictly for large fish-only systems.