There are around 120 known species of puffer fish, the second most poisonous creature on the planet after the Golden Poison Frog. The puffer fish is found in tropical waters worldwide, but they rarely go into the cooler waters.
Puffer fish are omnivorous animals and eat a variety and plants and animals. Puffer fish mainly feed on the algae that grows on the rocks and coral and also the invertebrates that inhabit these areas. Large species of puffer fish will also eat shellfish such as shrimp and crabs and molluscs.
Although there are a number of animals that prey on the puffer fish, these predators often meet with a nasty end. When the puffer fish is threatened it inflates it's body with air exposing the long, sharp, toxic spikes which normally intimidates the predator into retreating. If however, an animal does manage to eat the puffer fish, it will often be poisoned by the toxins in the spikes or the toxin that is released from the organs of the puffer fish when it dies.
Despite the toxins in the puffer fish, some animals such as sharks are able to eat the puffer fish without becoming harmed. It is important also to know that not all species of puffer fish are actually poisonous and these species are preyed upon by larger fish, sharks and also humans.
The smallest species of puffer fish in the world is the dwarf puffer fish (also known as the pea puffer fish and the pygmy puffer fish). The dwarf puffer fish is tiny growing to just an inch in length, which is a few centimetres. Despite the fact that the dwarf puffer fish is related to larger species of puffer fish, the dwarf puffer fish is not found in the sea but in just one river in India.
Not only does the puffer fish have unique defensive methods but they also have unique breeding methods. The male puffer fish guides the female puffer fish towards the shore where she releases between 3 and 7 eggs. The eggs of the puffer fish are extremely light and float on the surface of the water until they hatch in about a week's time. The puffer fish fry are still not fully developed and have a hard shell that protects them until their limbs begin to grow. The shell of the baby puffer fish then cracks off and the tail and fins develop. When the puffer fish is big enough, it will swim down and integrate itself into the reef community below.
Despite the puffer fish having such a deadly venom, there are some species of puffer fish whose meat is eaten in Japan and Korea as a local delicacy. Special chefs are trained to cut the fish so that the fish does not poison the consumer. Other species of puffer fish produce and release a toxin into their organs when they die to harm the thing that ate them.