Japanese Pufferfish

• Preparing it in Japan requires a specific licence, obtained after years of training and a practical examination, and certain organs are banned by law.
• The fish does not produce the toxin itself: it comes from bacteria taken in with its food, and fish reared in captivity on controlled feed turn out to be non-toxic.
• Its genome, published in 2002, is one of the most compact of any vertebrate, with very little non-coding DNA, which made it a reference for identifying genes in the human genome.
• Its genome was a key piece of genomics. It was sequenced in 2002, and it was chosen precisely because it is among the most compact vertebrate genomes known: around eight times smaller than the human genome yet with a similar number of genes, which made it a reference for locating human genes by comparison.
• Its toxin, tetrodotoxin, blocks the sodium channels of nerves and muscles and has no antidote. It is concentrated above all in the liver, gonads and skin.
• The fish does not make it itself: bacteria produce it, and the fish accumulates it through the food chain. Specimens reared in captivity on a controlled diet turn out to be non-toxic.
• Preparing it in Japan requires a licence, obtained after years of training and a practical examination.
• It inflates by swallowing water until it triples its volume, a defence that makes it almost impossible for a predator to swallow.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat & environment

Coastal and shelf waters of the north-western Pacific

Sources consulted: https://es.wikipedia.org/wiki/Takifugu_rubripes