Monday October 31, 2022
The term “zombie fish” is often associated with the image of anadromous fish like Chinook salmon using up the last of their energy reserves to spawn before dying. But what about fish that contain a toxin so potent, small amounts of it can send humans into a paralyzed, zombie-like state? Most species of pufferfish (family Tetraodontidae) contain a chemical toxin known as tetrodotoxin (TTX). This potent neurotoxin blocks vital communication pathways in nervous system cells. Symptoms include numbness in the mouth, muscle weakness, paralysis, nausea, and in some cases death. In the early 1980s, Harvard researcher and ethnobotanist Wade Davis claimed TTX was a common ingredient found in a powder called coupe poudre, used in traditional Haitian voodoo practices. This powder reportedly caused numbness and tingling in low doses and a near comatose or vegetative state in higher doses. Davis and other observers reported at the time that the “zombie powder” would lead to a state resembling death and even cause a foul rotting odor to emanate from the affected person. During a traditional voodoo practice, the person would ingest the powder and soon after be buried for a short amount of time before being exhumed by a bokor (voodoo priest). The bokor would then administer psychoactive chemicals from the jimson weed plant (Datura stramonium) that kept the person in a delirious or “zombified” state.
Researchers have since dismissed the majority of Davis’ claims as they lack scientific backing and many stories were exaggerated or altered. It was later discovered TTX was indeed found in the samples of coupe poudre procured in 1986, but it was in very small amounts that would likely not cause the eerie symptoms Davis described. Horror films often portray zombies as somewhat rigid creatures, lurching around aimlessly. This also matches the descriptions Davis recorded. It is well known that TTX can lead to paralysis due to blocked communication from the nervous system to the muscles, however, it is more of a limp paralysis, not the rigor mortis-like state one would see in “The Walking Dead” style zombies. It is believed the foul odor reported likely came from other causes related to the nearly paralyzed individual not being able to bathe or maintain other hygiene practices.
Although the effects and uses of TTX in voodoo practices in Haiti are now widely refuted, TTX poisoning from pufferfish consumption is a very real concern that continues to be relevant. Pufferfish, or “fugu,” is commonly served in Japan as a delicacy. It is intended to be prepared carefully so the organs containing the highest TTX levels are removed. Chefs preparing fugu must be qualified and the entire industry is highly regulated. TTX poisoning is relatively rare, but there have been outbreaks due to poorly prepared fish. In 2008, 141 people were affected by TTX poisoning after consuming fish from a market in Bangladesh. Seventeen of those cases ended up being fatal. TTX is typically considered a hazardous chemical, but recent studies have experimented with using altered doses for pain management in certain cancer patients. TTX found in pufferfish (and several other species) may not lead to a “Dawn of the Dead,” but it is a powerful chemical that appears to have potential usefulness in the medical field.
This post was featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.