Louisiana Fisheries
Current NewsAbout UsBiological InfoManagement InfoHabitat Info
Louisiana Fisherman Professionalism ProgramAquaculture InfoLegal & Socio-Economic Issues
Fisheries & PeopleResources & PublicationsFisheries FAQsSearch
LSU AgCenter Louisiana Sea Grant Louisiana Fisheries Louisiana Fisheries

Home > Resources & Publications > Newsletters & Magazines > Fins and Waters > 2009 > 04-09

Resources & Publications:  Fins & Waters

April 2009

Last July, a Chicago-area man was arrested for illegally purchasing research-grade tetrodotoxin (TTX). This toxin, found in certain fish species and in a few other animals, is more than 1,000 times more toxic than cyanide. The man who was arrested allegedly had intentions of assassination by use of TTX, which has a long and fascinating history of human use and misuse.

Tetrodotoxin is common name for anhydrotetrodotoxin 4-epitetrodotoxin tetrodonic acid. An incredibly potent neurotoxin, it has no antidote. The compound blocks action potentials in nerves by binding the “fast” sodium channels in nerve cell membranes. It was originally described in the fish order Tetraodontiformes, which includes the pufferfish, porcupinefish, ocean sunfish and triggerfish, but not all of these carry the toxin. TTX is actually the product of certain bacteria, including Pseudoalteromonas tetraodonis and some species of Pseudomonas and Vibrio. The latter are the most common source of bacteria associated with TTX production, particularly the common species Vibrio alginolyticus. The toxin is accumulated in fish via ingestion: The fish eat invertebrates that have accumulated the toxin. Other aquatic vertebrate animals, including some amphibians, have also demonstrated high levels of TTX.

In humans, TTX blocks the fast sodium current in muscle cells, preventing contraction. When the fast sodium current of the cells of the diaphragm are paralyzed, death occurs when breathing ceases. Symptoms of TTX poisoning usually develop within a half hour of ingestion, and death has occurred as quickly as within 17 minutes of ingestion. Other symptoms may include numbness of the lips and tongue, sweating, headache, weakness, ataxia, incoordination, tremor, paralysis, cyanosis, aphonia, dysphagia, seizures, dyspnea, bronchorrhea, bronchospasm, coma, hypotension, nausea, vomiting, diarrhea and abdominal pain.

The first recorded case of tetrodotoxin poisoning was by Captain James Cook, who recorded his crew eating some local tropic pufferfish and then feeding the remains to the pigs kept on board. The crew experienced numbness and shortness of breath, and the pigs died. This is a typical case of TTX poisoning from puffers, which usually have little or no toxin in the flesh but lethal concentrations in the skin, entrails and particularly the liver. This characteristic is said to make for the most adventurous sushi dining experience (now banned) in Japan, where expert sushi chefs carefully prepare the meat of certain large puffers to make fugu, carefully avoiding any contact with skin or entrails. Even a slight nick of the liver with the knife used to prepare the sashimi or sushi can lead to death. The slightest tingling of the lips after the meal signifies that the diner has bravely avoided a completely unnecessary brush with death. In fact, most of the cases of TTX poisoning in Japan have been from fishermen preparing their own catches. Japanese health bureau s statistics documented 20 to 44 incidents of fugu poisoning per year between 1996 and 2006, leading to 34 to 64 hospitalizations and 0 to 6 deaths per year, for an average fatality rate of about 6.8 percent.

Around the world, most reports of TTX poisonings have been associated with the consumption of puffers from waters of the Indo-Pacific ocean regions. A few cases, including fatalities, have been reported from pufferfish from the Atlantic Ocean, Gulf of Mexico and Gulf of California.

Louisiana waters are home to some eight species of pufferfish and three porcupinefishes. The most common may be the little least puffer, Sphoeroides parvus, which, when accidentally caught in a shrimp net will puff up to give the appearance of marshmallows mixed in with the shrimp. Little data exists on TTX in our species, but recent research from Japan indicates that similar species often tend to exhibit only traces of TTX. Other recent research on some Indian River Lagoon, Florida, puffer species indicates that saxitoxin and not tetrodotoxin may by the culprit in poisonings from some puffers. Saxitoxin is one of the toxins associated with paralytic shellfish poisoning. With many of the symptoms of saxitoxin poisoning being similar to those of TTX, it is clear that any consumption of these species should be avoided.

A celebrated, but unproven, intentional application of TTX could be in the creation of the Haitian zombie legend. In the 1970s, a Harvard ethnobotanist named Wade Davis reported that he had procured samples of “zombi powder” from voodoo sorcerers in Haiti. The samples included numerous ingredients, including ground human bones, but invariably contained TTX from powdered puffer fish. Davis reported that individuals who had committed acts against fellow villagers were sometimes sold to the sorcerers as slaves. The sorcerer would poison the individual with a powder applied to the skin (and TTX can be absorbed through the skin) to induce a near-death coma. Following entombment, the sorcerer would retrieve the unfortunate person, and perhaps administer additional powerful drugs, and enslave the near-brain-dead zombie. A few cases of psychotic people showing up in their villages years after their burials have been allegedly documented, though subsequent analysis of some zombie powders have been inconclusive. Davis has maintained that zombification is an imprecise process, with some people killed outright and others merely sickened, but that the fact that most Haitians believe in this form of social exile makes it a real phenomenon. 

What became of the recent arrest for TTX assassination plans? It was also alleged that the arrested gentleman had previously posted an Internet solicitation for someone to kill his wife in exchange for $8,000 and an AK-47 assault rifle, and was in possession of documents about how to poison people.  In the latest news of the case, he was arraigned in federal court for the possession of the illegal toxin.

Back to Top


Louisiana Fisheries LSU AgCenter Louisiana Sea Grant