by Gary Podolsky MD
Takifugu is a genus of pufferfish, often
better known under the Japanese name Fugu (??
or ?).. Pufferfish defend themselves by inflating their bodies to
several times normal size and by poisoning their predators. These
defenses allow the fish to explore actively without much fear of
fish is highly toxic, but despite this — or perhaps because of it
— it is considered a delicacy in Japan. Pufferfish contain lethal
amounts of the poison tetrodotoxin in their internal
organs, especially the liver and the ovaries, but also in the skin
and the testicles. Therefore, only specially licensed Fugu chefs
can prepare and sell fugu to the public, and the consumption of
the liver and ovaries is forbidden because they contain the highest
concentration of tetrodotoxin. However, because small amounts of
the poison give a special desired sensation on the tongue, these
parts are considered the most delicious by some gourmets. Every
year a number of people die because someone has underestimated the
amount of poison in the fish. Domestically in Canada Fugu is a rare
delicacy but travelers may encounter Fugu preparations.
poison paralyzes the muscles while the victim stays fully conscious,
and eventually dies from respiratory failure. There is no antidote,
and the standard medical approach is to try supportive therapy until
the poison wears off. The fish is also featured prominently in Japanese
art and culture. Fugu is also popular in Korean cuisine.
fish's main lethal defense, is the neurotoxin contained in its internal
visceral organs (the ovaries and the liver and to a lesser extent
the intestines) and in the skin. Only minute amounts exist in the
muscles and blood. This makes the fugu a lethal meal for most predators,
including the occasional human.
toxin- tetrodotoxin ( anhydrotetrodotoxin 4-epitetrodotoxin)
is 1200 times deadlier than cyanide. The pufferfish does not
create the poison itself. This poison is generated by the bacteria
Pseudomonas and is also found in other marine animals
such as the Blue-Ringed Octopus , and Cone
Snails and also in some newts. These animals use the tetrodotoxin
as a defence. Blue octopus bites and cone snail envenomations are
medical emergancies as theyare frequently lethal.
fish obtains the bacteria by eating food containing these bacteria.
Pufferfish born and grown in captivity do not accumulate tetrodotoxin
until they ingest the poison-producing bacteria, often by eating
tissues from a toxin-producing fish. Also, some fish are more poisonous
than others. Some fish may have enough poison to kill 30 adults.
has been consumed in Japan for a long time, although its historic
origins are unclear.. Strict fishing regulations now protect fugu
from being decimated.
prices rise in the fall and peak in winter, which is the best time
to eat fugu, as they fatten to survive the cold. The fugu is shipped
to the restaurant alive and stored in the restaurant in a large
tank, usually prominently displayed. As fugu are aggressive and
have sharp teeth, in captivity the mouths of fugu are often sewn
shut to prevent the fish from injuring each other.
1958, only specially licensed chefs have been allowed to prepare
and sell fugu to the public. The fugu apprentice needs a 2-3 year
apprenticeship before being allowed to take an official test. The
test consists of a written test, a fish identification test, and
a practical test of preparing fugu and then eating it. Only 30 percent
of the applicants pass. The other 70 percent do not die from poisoning
but fail from a small mistake in the long and complicated procedure
of preparing the dish. Due to this rigorous examination process,
it is considered safe to eat the sliced fugu sold in restaurants
special knife called fugu hiki is traditionally
used to slice fugu and it is usually stored carefully
in a separate location from other knives.
Winnipeg there are no registered Fugu Chefs. Given the very small
market for Fugu and the need to keep it fresh make its unavailability
a certainty in the near future. In the US some Fugu restaurants
serve fish that do not contain any toxin.
fugu sold nowadays comes from fish with only a small amount of toxin.
Selling or serving the most toxic liver is illegal in Japan, but
this "forbidden fruit" is still sometimes eaten by amateur
cooks, often with fatal results. After several homeless people died
from eating fugu organs that had been discarded into an insecure
trashcan, restaurants in Japan are now required to store the poisonous
inner organs in specially locked barrels that are later burned as
hazardous waste. Prepared fugu is also often available in grocery
stores which must display official documents which license them
to distribute fresh fugu.
fugu connoisseurs love the taste and the texture of the fugu, many
people actually find it rather bland and tasteless. Some professional
chefs prepare the fish so that there is a minute amount of poison
in the meat, giving a prickling feeling and numbness on the tongue
and the lips.
tetrodotoxin is very stable and is not affected by the heat
of cooking . It does not cross the blood-brain barrier
which leaves the victim fully conscious while paralyzing the remainder
of the body.
first symptoms occur 15 minutes to several hours postingestion of
tetrodotoxin containing fugu. In some cases this may occur up to
20 hours after ingestion. Initial symptoms include lip and tongue
paresthesias, followed by facial and extremity paresthesias and
numbness. Salivation, nausea, vomiting, and diarrhea with abdominal
pain develop early.
can occur within 4-6 hours from respiratory muscle paralysis and
respiratory failure. If the victim survives the first 24 hours,
he or she usually recovers completely.
is no known antidote and treatment consists of emptying the stomach,
feeding the victim activated charcoal to bind the toxin and taking
standard life-support measures to keep the victim alive until the
effect of the poison has worn off.
toxicologists are currently working on developing an antidote to
available fugu in supermarkets or restaurants is very safe and,
while not unheard of, poisoning from these products are very rare.
Most deaths from fugu occur when untrained people catch and prepare
the fish, accidentally poisoning themselves. In some cases they
even eat the highly poisonous liver on purpose as a delicacy. As
not all fishes are equally poisonous so do not always lead to death,
but small amounts of tetrodotxin give only the desired numbness
on the lips and tongue during eating and shortly thereafter. However,
in many cases this numbness of the lips is only the first step of
a lethal fugu poisoning.
sources claim that about 100 people die each year from fugu poisoning,
while others sources say only 10 to 20 per year, and still others
state only 1 person dies each year from fugu.
to the Fugu Research Institute, 50 percent of the victims were poisoned
by eating the liver, 43 percent from eating the ovaries and 7 percent
from eating the skin.
are some reports of completely paralyzed but fully conscious victims
that were believed to be dead, but woke up a few days later or just
before being cremated. In some parts of Japan a fugu victim is put
next to his coffin for three days to verify the death. If the body
does not decompose, it is not yet dead.
at Nagasaki University have bred a non-toxic variety of. The non-toxic
version is said to taste the same, but be completely safe for consumption.
Japanese cities have one or more fugu restaurants. They may be clustered
together as past regulations had placed limits on where they may
open their store and also the waterfront location of restaurants
made it easier to have fugu delivered fresh.
is a famous restaurant specializing in fugu in the Ginza
district in Tokyo. Zuboraya is a popular Osakan
restaurant chain. The people of Tokyo buy Takifugu rubripes
at the Tsukiji fish market — after the highly toxic
liver has been removed. Few restaurants in the United States carry
fugu and if it is available it does not contain any tetrodotoxin
Travelers to Japan and Korea
may encounter Fugu restaurants, which are carefully regulated and
very safe. The risk from eating fugu remains from ingesting fish not
prepared by professionals. Any catches of puffer fish or other tetrodotoxin
bearing species should never be eaten. Travelers to foreign countries
merely need to be educated so that they do not eat amateur preparations
of suspect catches.