The name Puffer fish is used for a wide range of different species in the family Tetraodontidae within the order Tetraodontiformes. The puffer fish is also known as globe fish, ballon fish, blow fish and swell fish. All these names allude to a remarkable trait exhibited by these fishes; the ability to inflate the body and puff up when threatened.
The puffer fishes are close relatives of the porcupine fishes; another group of fishes that can puff up just like puffers. The porcupine fish is however covered in spines and this distinguishes it from the puffer fish.
The family Tetraodontidae comprises 185 decribed species of fish and many of the have been successfully kept by aquarists. Fat puffers, i.e. species belonging to the genus Arothron, are especially popular, but aquarists have managed to keep puffers from other genera as well.
In wild, you can encounter pufferfish from 45° latitude north to 45° latitude south. A majority of the species lives in the ocean, but many of those are capable of venturing into brackish or fresh water to feed or breed. There are also several species of freshwater puffers. Pufferfishes that live in the ocean will typically stay near coral reefs close to the shore, but some prefer to live in the deep sea.
As you can see, the family Tetraodontidae is a diverse family and it is very important to research the species you are interested in before you make a purchase. Never force a puffer to live in an environment that is unhealthy for it in the long run. A marine species capable of venturing into brackish environments now and then might for instance be able to survive for a while in a freshwater aquarium, but this doesn’t mean that it suddenly becomes a freshwater puffer.
The abovementioned genus Arothron is a good choice if you want to keep puffers in your saltwater aquarium. These puffers commonly perceived as extremely cute by humans, since they are equipped with large expressive eyes and can vocalise using their snout. Many aquarists swear that each of their Arothron puffers has its own unique personally, just like a cat or dog.
The pufferfish is capable of inflating itself since it has a highly flexible and elastic stomach which can be filled with water or air. The puffer fish might look cute when inflated, but you should never scare your fish into inflating itself. Puffing up is highly stressful for the fish and air can become trapped inside its body. If the trapped air prevents the fish from deflating, the puffer will die. If a puffer is frightened when out of water it will suck in air instead of water and this is also dangerous for the fish.
Puffers are highly toxic and contain the poison tetrodotoxin. This is one of the most potent toxins in nature and a does of 1-2 mg is enough to kill an adult human. Puffer fish is considered a delicacy in Japan, but it must be prepared by en exceptionally skilled chef to be safe for consumption. Puffer fish poisoning can result in death within 4-6 hours.