Porcupinefish

About

Found on shallow reefs across the globe, this porcupinefish, known scientifically as Diodon holacanthus, is one of those species with a personality that tends to win people over pretty quickly. It has that classic puffer look. A rounded body covered in long, sharp spines that lay flat until the fish feels threatened, at which point it inflates and becomes an unmistakable spiky ball. Its wide-set eyes and slightly goofy expression only add to the charm. In the wild it ranges across tropical and subtropical seas worldwide, from the Atlantic coast of the Americas all the way through Indo-Pacific waters, turning up on coral reefs, rocky substrates, and even muddy open bottoms. Juveniles often drift with floating Sargassum mats early in life before settling into more permanent territory. It feeds nocturnally on hard-shelled prey, mollusks, crabs, sea urchins, using its fused beak-like teeth to crack shells with ease. In the aquarium that same feeding style means any invertebrates you value are at serious risk. It is not a particularly fast or agile swimmer, which makes it entertaining to watch but also means tankmates should be chosen carefully. The inflating behavior, while fascinating, should never be deliberately triggered as it can cause real harm to the fish.