With their big eyes Pufferfish and Porcupinefish certainly look cute and can make great photographic subjects.

Porcupinefish are closely related to pufferfishes but unlike pufferfishes, they have only a single plate of fused teeth in each of the upper and lower jaws. Both groups of fishes are able to defend themselves by inflating their bodies with air or water until they are almost completely spherical. Porcupinefish also have heavier spines on their body (hence the name porcupine).

Most pufferfish and porcupinefish are poisonous to eat and are the second most poisonous vertebrate in the world (the first being the Golden Poison frog). Their internal organs contain a powerful poison called tetrodotoxin.

Pufferfish Tetrodotoxin is 100 times more poisonous than potassium cyanide.

The skin and organs (e.g. liver) of the pufferfish can contain levels of tetrodotoxin sufficient to produce paralysis of the diaphragm and death due to respiratory failure. Toxicity varies between species and at different seasons and geographic localities, and the flesh of many pufferfish may not always be dangerously toxic or fatal.

However, at near-lethal doses it can leave a person in a state close to death for several days, while the person continues to be conscious.