In my physiology class, we're learning about the nervous system and there's an interesting section on neurotoxins I thought I'd share.
A neurotoxin is a poiosn that acts on the nervous system. Puffer fish contain a toxin called TTX which is very potent and works by blocking voltage-gated sodium channels needed to produce an action potential. Oddly enough, puffer fish, or fugu as it's called in Japan, is considered a prized delicacy. It's very popular for it's taste and the tingling sensation around the lips one gets when eating it. The toxin is concentrated in certain areas of the fish such as the liver (which has been claimed as the best tasting part) and cannot be destroyed by cooking. Therefore, preparation of the fish must be done by licensed chefs who are able to remove the organs without contaminating the edible parts. If TTX is ingested, the body becomes paralyzed and the victim is unable to breathe.
This toxin is so lethal that in 1983, Japan banned the sale of puffer fish livers. This makes me wonder why fugu is such a popular dish when you're basically risking your life every time you eat it.
Puffer fish is an easily recognized type of fish due to ability to transform and enlarge its body in a split of a second. There are more than 120 species of puffer fish which live mostly in the warm waters of the Indian, Pacific and Atlantic Oceans, with only 30 species that are living in the freshwater. Some species move from marine to brackish or fresh water during the breeding season. Although number of puffer fish is stable in the wild, they are vulnerable due to overfishing, pollution of the ocean and loss of natural habitats.