It's also broadly used for a fish that can swell its body and more specifically for the genus fugu that only lives in the waters surrounding Japan. The fugu is a plump little fish with absurdly small fins that is barely able to swim, hence it has developed two forms of defense. According to the American FDA, there is a 50 percent fatality rate among those unlucky enough to ingest the poison. Puffer protect themselves from self-poisoning with a mutation in the protein sequence of the sodium channel pump. This prevents the toxin from recognizing and entering the channel.
Puffer can therefore store high concentrations of tetrodotoxin in various organs quite safely.
In spite of this, the last meal for an unlucky few is fugu with some tetrodotoxin on the side. The most notorious was the death of Mitsugora Bando VIII, a famous Kabuki actor and national treasure, in 1975. However, neither the danger nor the extortionate price seems to deter customers. To create a living organism there must be a design manual that dictates whether there are arms or fins, how many and where they are positioned on the body and so on. This design manual or recipe is known as the genome.