These odd shaped guys, with their big cow eyes and silly grin, are commonly seen throughout the Caribbean hiding in reef crevices or overhangs during the day. They are a guest favorite during our daily two tank dives. Sometimes referred to as “Pufferfish” “Balloonfish“ or “Blowfish” , Porcupine fish are nocturnal, carnivorous predators, specializing in eating hard-shelled prey. Their strong beak-like mouth is used to seize and crush prey such as urchins, crabs, snails, and clams. Porcupine fish also possess thick, rubbery lips to protect them from being injured by the spines and broken shells of the prey they eat. At night, porcupine fish can be observed actively combing the reef for food and investigating sandy areas, crevices, and caves where their prey might be found.
When a Porcupine fish is frightened, it pumps water into its body and can inflate up to three times its normal size until it looks like a prickly soccer ball. Few predators are large enough, or brave enough, to swallow a fish in this state. Left to itself, the porcupine fish deflates and its long spines lie flat against its body.
Commonly seen on all of the St. Croix dive sites, Porcupine fish are generally shy and wary of divers, they do not defend territories, and will attempt to escape and find shelter at the first sign of a threat. To observe these fish, stay at a distance. If the diver is patient and approaches slowly, on occasion, the Porcupine fish will allow a diver to get close.