Porcupinefish are part of a family of fish that are called Diodontidae, and are quite often more commonly called the pufferfish, or the blow fish.
Inflated Porcupine Fish
They are not in reality pufferfish, but are related to them. The Porcupine fish sports on its body a wide array of spines that stand erect when the fish inflates and are very often mistaken for pufferfish.
The Porcupine fish has the unique ability of being a fish that can blow up their bodies, or inflate them. They do this by swallowing air or water and will become literally as rounds as a basket ball.
The porcupine fish can enlarge himself almost double the size that he was. Scientists think this is another method of self defense for the porcupine fish.He does this to lower the predators who can prey on him to about half what they normally would be if he did not have this ability.
His second and probably best defense is that he bears many rows of
very sharp spines, and when the porcupinefish blows himself up to full volume, they become erect, and stand straight up and out.
Some species of Porcupine fish also bear a venom, or poison that is emitted from the spines. They have what is called a Tetrodoxin within the skin as well as or in addition to in their intestines.
As a result of their great methods of self defense the porcupine fish has very few predators that will take them for food.
Adult porcupinefish are sometimes a meal for larger fish such as the shark and the Orca, or whale, although this is only rare in occurence.
The younger or juvenile porcupine fish may sometimes be taken and eaten by larger tuna or by dolphins.