Fugu - Japanese puffer fish
Takifugu is a genus of puffer fish, often
better known by the Japanese name Fugu (Japanese: 河豚, literally "river
pig"). There are 25 species belonging to the genus Takifugu, which can be
found worldwide from about 45� latitude north to 45� latitude south, mostly
in salt water, but sometimes also in fresh water or brackish water. Their
diet consists mostly of algae, mollusks, invertebrates and sometimes
crustaceans. The fish defend themselves by inflating their bodies to several
times normal size and by poisoning their predators. These defences allow the
fish to actively explore their environment without much fear of being
The fish is highly toxic, but despite this � or perhaps because of it � it
is considered a delicacy in Japan. The fish contains lethal amounts of the
poison tetrodotoxin in the internal organs, especially the liver and the
ovaries, but also in the skin and the testicles. Therefore, only specially
licensed chefs can prepare and sell fugu to the public, and the consumption
of the liver and ovaries is forbidden. But 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 they underestimate the amount of poison in the consumed
The poison paralyzes the muscles while the victim stays fully conscious, and
eventually dies from asphyxiation. There is currently no antidote, and the
standard medical approach is to try to support the respiratory and
circulatory system until the effect of the poison wears off. The fish is
also featured prominently in Japanese art and culture.
The Fugu fish
There are 25 species belonging to the genus Takifugu (formerly known as Fugu,
with the exception of one remaining Fugu species). Takifugu can be found
worldwide from about 45� latitude north to 45� latitude south, mostly in
salt water near coral reefs or the shore, but some species also live in
fresh water or brackish water. Their diet consists mostly of algae, mollusks,
invertebrates and sometimes crustaceans. All fishes in the tetradon family
have strong teeth that may grow too long if the fish cannot consume abrasive
food. Fugu can bite if provoked. Not all species are studied in detail, but
the most researched takifugu is Takifugu rubripes, due to the commercial
consumption and breeding of the fish. Takifugu rubripes, for example, breeds
from March to May and lays eggs attached to rocks at a depth of around 20m.
Fugu can also change color over time, and they get a darker or lighter color.
This helps them to camouflage. A very dark color may be a sign of stress or
The pear-shaped Takifugu, like all pufferfish, are not fast swimmers as they
mainly use their pectoral fins for propulsion, but they are very
manoeuvrable and able to hover, swim backwards, and change direction much
more quickly than most other types of fish. As a result, they are rarely
found in open water and prefer to stay relatively close to the sea bed where
they can explore complex environments such as oyster beds, seagrass meadows,
and rocky reefs. Nevertheless, these fish are very curious and active, and
in some cases even aggressive against other fugu or other fish. In the event
of danger, the fish inflates itself by filling its extremely elastic stomach
with water (or air when outside of the water) until the fish is almost
spherical (hence the name blowfish or pufferfish).
Previously, it was unknown how pufferfish inflation took place. Recently,
however, Dr. Peter Wainwright completed his analysis on the series of muscle
actions which allow a pufferfish to inflate. First, the pufferfish fills its
mouth with water. Then, it seals its mouth using a special valve at the
bottom of the mouth. This valve flaps upward and covers the entire mouth of
the fish. Next, a branchiostegal ray (a modified gill arch) pushes the water
down the esophagus into the stomach. The extremely elastic stomach then
expands. Depending on the species the fugu can achieve an almost perfect
The fish's main defense, however, is the neurotoxin contained in its
internal organs, mainly the ovaries and the liver, to a lesser extent in the
intestines and the skin, and only minute amounts in the muscles and blood.
This makes the fugu a lethal meal for most predators, including the
The toxin is called tetrodotoxin, or more precisely anhydrotetrodotoxin
4-epitetrodotoxin and is about 1200 times deadlier than cyanide. This poison
can also be found in other animals such as the Blue-Ringed Octopus, Cone
Snails, and even some newts. The pufferfish does not create the poison
itself; rather it is generated by the bacteria Pseudomonas within the fish.
The fish obtains the bacteria by eating food containing these bacteria.
Pufferfish that are born and grown in captivity do not produce tetrodotoxin
until they receive some of the poison-producing bacteria, often by eating
tissues from a toxin-producing fish. Also, some fish are more poisonous than
others. Each fish has enough poison to kill around 30 adult humans.
Apparently due to some unknown selection pressure, intronic and extragenic
sequences have been drastically reduced within this family. As a result,
they have the smallest-known genomes yet found amongst the vertebrate
animals, while containing a genetic repertoire very similar to other fishes
and thus comparable to vertebrates generally. Since these genomes are
relatively compact it is relatively fast and inexpensive to compile their
complete sequences, as has been done for two species (Takifugu rubripes and
Takifugu rubripes for sale to master fugu chefs at the Tsukiji fish market
in Tokyo � after the highly toxic liver has been removed.Fugu has been
consumed in Japan for a long time, although its historic origins is unclear.
Bones of fugu have been found in several shell mounds called kaizuka in
jomon period that date back more than 2,300 years. The Tokugawa shogunate
(1603-1868) prohibited the consumption of fugu in Edo and its area of
influence, yet it became common again as the power of the shogunate
weakened. In Western regions of Japan, where the influence of the Government
was weaker and fugu was easier to obtain, various cooking methods were
developed to safely eat these fish. During the Meiji Era (1867-1912) fugu
was again banned in many areas of Japan. Fugu is also the only delicacy
officially forbidden to the Emperor of Japan, for his own safety.
A rakugo, or humorous short story, tells about three men that prepared a
fugu stew, but were not sure about how safe it was. To test the stew, they
gave some to a beggar. When they checked on the beggar later, he was still
healthy, so they ate the stew. Afterwards they met the beggar again and were
delighted to see that he was still in good health, reassuring the men. After
that encounter, the beggar, who had in fact saved the stew, knew that the
stew was safe and he could eat it. The three men had been fooled by the wise
The most prestigious edible species is the torafugu or Tiger Blowfish (T.
rubripes), which is also the most poisonous. Other species are also eaten,
as for example T. pardalis, T. vermicularis, and T. porphyreus. The table at
the end of the article shows which species contain body parts that can be
consumed according to the Japanese Ministry of Health and Welfare. Other
genera that can be consumed according to them include the puffers
Lagocephalus and Sphoeroides, and the related porcupinefish of the genus
The high demand of fugu has led to overfishing. Strict fishing regulations
are now in place to protect the fugu population from being depleted. Most
fugu nowadays is harvested in the spring during the spawning season, and
then farmed in floating cages in the Pacific Ocean. The largest wholesale
market for fugu in Japan is in Shimonoseki.
Fugu 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 avoid the fish injuring
each other. Prepared fugu is also often available in grocery stores which
must display official documents which license them to distribute fresh fugu.
Since 1958, only specially licensed chefs can prepare and sell fugu to the
public. The fugu apprentice needs a two- or three-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% of the applicants pass the test. This, of course, does
not mean that 70% die from poisoning; rather, they made a small mistake in
the long and complicated procedure of preparing the dish. Due to this
rigorous examination process, it is generally safe to eat the sliced fugu
sold in restaurants or markets.
Furthermore, most 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 the years following Japan's defeat in World
War II, when several homeless people died from eating fugu organs that had
been discarded into insecure trashcans, restaurants in Japan were required
to store the poisonous inner organs in specially locked barrels that are
later burned as hazardous waste.
A dish of fugu can cost easily �5000 (ca. US$50) but it can be found for as
little as �2000 yen (ca. US$20), and a full course fugu meal can cost
between �10,000 and �20,000 (ca. US$100 to US$200) or more. Due to the
expense of fugu, the fish is sliced very carefully to obtain the largest
possible amount of meat without the poison. A special knife called fugu hiki
is traditionally used to slice fugu and it is usually stored carefully in a
separate location from other knives.
While 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. The most
popular dish is fugu sashimi, also called Fugu sashi or tessa, sliced so
thin that the pattern of the plate can be seen through the meat. These
plates are often decorated so that the removal of the slices will be
aesthetically pleasing as well. The fins of the fish are also fried and
served in hot sake, a dish called Fugu Hire-zake.
Vegetables and fugu can also be simmered as Fugu-chiri, also called techiri,
in which case the very light taste of the fish is hard to detect among the
taste of the vegetables and the dip. Fugu can also be eaten deep fried as
Fugu Kara-age. The more poisonous testicles of the fugu can also be eaten;
they contain a milky liquid and taste slightly salty. This is also
considered to be an aphrodisiac. If the spikes in the skin are pulled out,
the skin can also be eaten as part of a salad called yubiki.
In several remote locations, complex pickling processes have been devised
which allow the poisonous parts of the fugu to be eaten. While the exact
methods are kept secret, they involve long and heavy saturations in sake and
salt for over three years.
Most Japanese cities have one or more fugu restaurants. They may be
clustered together, as past regulations had placed limits on where the
stores may be opened, and also the location of restaurants made it easier to
have fugu delivered fresh. A famous restaurant specializing in fugu is
Takefuku, a restaurant in the Ginza district in Tokyo. Zuboraya is another
popular chain in Osaka.
Few restaurants in the United States serve fugu. As of 2003, only seventeen
restaurants were licensed to do so; twelve in New York, and one in
Seattle. The fugu is first cleaned of the most toxic parts in Japan, and
then is freeze-flown to the USA under licence, in purpose-built, clear,
plastic containers. The fugu chefs for the US restaurants are trained
under the same rigorous specifications as in Japan.
Tetrodotoxin is a very potent neurotoxin and shuts down electrical signaling
in nerves by binding to the pores of sodium channel proteins in nerve cell
membranes. The tetrodotoxin is very stable and not affected by the heat of
cooking. It does not cross the blood�brain barrier, leaving the victim fully
conscious while paralyzing the remainder of the body. In animal studies with
mice, 8 μg tetrodotoxin per kg body weight killed 50% of the mice. The
pufferfish itself has immunity to the poison due to a mutation in the
protein sequence of the sodium channel pump on the cell membranes.
If an ingested dose of the fugu's poison is lethal, as more and more muscles
are paralyzed, symptoms may include dizziness, exhaustion, headache, nausea
or difficulty breathing. For 50% to 80% of the victims, death follows within
four to 24 hours. The victim remains fully conscious throughout most of the
ordeal, but cannot speak or move due to paralysis, and soon also cannot
breathe and subsequently asphyxiates. If the victim survives the first 24
hours, he or she usually recovers completely.
There 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. Japanese toxicologists in several medical research
centers are currently working on developing an antidote to tetrodotoxin.
As mentioned above, commercially available fugu in supermarkets or
restaurants is very safe and, while not unheard of, poisoning from these
products is 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, this may not always lead to death, but
sometimes give little more than the desired numbness on the lips and tongue
while eating and shortly thereafter. However, in many cases this numbness of
the lips is only the first step of a lethal fugu poisoning.
Some 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. This reported variation may be the result
of different sequences of years being studied, as for example in 1958, the
first year the preparation of fugu required a special license in Japan, 176
people died of fugu poisoning. According to the Fugu Research Institute, 50%
of the victims were poisoned by eating the liver, 43% from eating the
ovaries and 7% from eating the skin. One of the most famous victims was the
famous Kabuki actor and "living national treasure" Bandō Mitsugorō VIII, who
requested four servings of fugu liver and died after eating in 1975. The
fugu chef of the restaurant could not refuse the request from such a
prestigious artist. Subsequently, the chef lost his license for breaking the
There are some reports of completely paralyzed but fully conscious victims
that were believed to be dead, and 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.
The pufferfish is also reported to be one of the main ingredients used in
voodoo to turn people into zombies. According to ethnobotanist Wade Davis,
the pufferfish is the key ingredient in the first step of creating a zombie,
where the tetrodotoxin creates a 'death-like' state. In the second step,
hallucinogens are used to hold the person in a will-less zombie state. There
was considerable skepticism to Davis's claims; he was widely accused of
fraud, and there has been no final statement as to the veracity of his
findings. 
Scientists at Nagasaki University have reportedly succeeded in breeding a
non-toxic variety of torafugu by restricting the fish's diet. With over 4800
fish raised and found to be non-toxic, they are fairly certain that the
fish's diet and digestive process are what actually produce the toxins that
make it deadly. The non-toxic version is said to taste the same, but be
completely safe for consumption.
Fugu and Yellowtail by Hiroshige (1832)The popularity of fugu in Japan is an
interesting phenomenon. Fugu is a very expensive fish, has some potentially
lethal side effects, and is by most people considered to have a very weak
taste (although many Japanese gourmets would disagree). The combination of
these factors would normally give humans a low preference for its
consumption. However, it seems one of the attractions of the low-flavored
fish is the risk of potential death, regardless of how low that actual
likelihood stands in a commercial restaurant. It can be assumed that the
fish would be much less popular if it were not so poisonous.
The Japanese poet Yosa Buson (1716�1783) expressed some of this feeling in a
I cannot see her tonight.
I have to give her up
So I will eat fugu.
In the Kansai region the slang name teppo, (鉄砲) meaning rifle or gun is used
for the fish. This is a play of words on the verb ataru (当たる), which can
mean either to be poisoned or to be shot. In Yamaguchi Prefecture, the
pronunciation fuku is common instead of fugu. The former means good fortune
whereas the latter is a homonym for disabled. The Tsukiji fish market fugu
association holds a service each year at the height of the fugu season,
releasing hundreds of caught fugu into the (rather polluted) Sumida River. A
similar ceremony is also held at another large market in Shimonoseki.
Perhaps the most well-known fugu story in America was when the fictional
character Homer Simpson of the TV show The Simpsons ate fugu served by an
amateur chef. Due to the chef's lack of fugu-preparation knowledge, Homer
was given 24 hours to live (before his "heart would explode"), during which
he vowed to do all the things he always meant to do but never got around to.
However, most of the time was spent either asleep, with his senile father,
or in jail. He did survive the 24 hours in the end, to the joy of his family
and friends. See "One Fish, Two Fish, Blowfish, Blue Fish".
An episode of Columbo also involved fugu poisoning, this time, a murder. The
perpetrator injected fugu poison through the cork into a bottle of wine. The
CSI: NY episode "Grand Master" included a novel fugu poisoning murder.
Another television show, Nip/Tuck features an episode where a character
tries fugu as a way to show his son that he is a "Real man".
In Japanese television, Chairman Kaga, the eccentric and flamboyant host of
the cooking show Iron Chef, died of fugu poisoning after the regular run of
the series ended. The Chairman was killed off partly because the actor
portraying him, Kaga Takeshi, had prior commitments that prevented him from
reprising his role in an Iron Chef special.
Lanterns can be made from the bodies of preserved fugu. These are
occasionally seen outside of fugu restaurants, as children's toys, as folk
art or as souvenirs for tourists. Fugu skin may also be made into everyday
objects like wallets or waterproof boxes.
There is a fugu museum in Osaka.
In Germany the fugu was used by the early Green Party for a political joke
on their Social Democrat counterparts in the first Red-Green coalition in
the state of Hesse in 1985. During a night session to finalize the coalition
agreement the Greens suddenly demanded that Hesse join the (fictional)
"Shanghai Fugu Agreement" which was accepted by their tired counterparts and
officially endorsed as Hesse government politics. The aim of the fictional
agreement was explained to be the saving of consumers' lives by easing
restrictions on working permits for fugu chefs internationally. The prank
took years to be discovered.
(Article based on
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