Candirú
Encyclopedia
Candiru or candirú (Spanish
), also known as cañero, toothpick fish, or vampire fish, are a number of genera of parasitic freshwater
catfish
in the family
Trichomycteridae
; all are native to the Amazon River
. Although some candiru species have been known to grow to a size of 16 inches (~41 cm) in length, others are considerably smaller. These smaller species are known for an alleged tendency to invade and parasitise the human urethra
; however, despite ethnological reports dating back to the late 19th century, the first documented case of the removal of a candiru from a human urethra did not occur until 1997, and even that incident has remained a matter of controversy.
The definition of candiru differs between authors. The word has been used to refer to only Vandellia cirrhosa, the entire genus Vandellia
, the subfamily Vandelliinae
, or even the two subfamilies Vandelliinae and Stegophilinae
.
) inhabit the Amazon
and Orinoco
rivers of lowland Amazonia, where they constitute part of the Neotropical fish
fauna. Candirus are hematophagous and parasitize the gills of larger Amazonian fishes, especially catfishes of the family Pimelodidae
(Siluriformes).
of attacks on humans abound, very few cases have been verified, and some alleged traits of the fish have been discredited as myth or superstition.
in 1829, who never actually observed it, but rather was told about it by the native people of the area, including that men would tie a ligature around their penis while going into the river to prevent this from happening. Other sources also suggest that other tribes in the area used various forms of protective coverings for their genitals while bathing, though it was also suggested that these were to prevent bites from piranha. Martius also speculated that the fish were attracted by the "odor" of urine. Later experimental evidence showed this to be false, as the fish actually hunt by sight and have no attraction to urine at all.
Another report from French naturalist Frances de Castelnau in 1855 relates an allegation by local Araguay fisherman, saying that it is dangerous to urinate in the river as the fish "springs out of the water and penetrates into the urethra by ascending the length of the liquid column." While Castelnau himself dismissed this claim as "absolutely preposterous," and the fluid mechanics
of such a thing occurring literally defy the laws of physics, it remains one of the more stubborn myths about the candiru. It has been suggested this claim evolved out of the real observation that certain species of fish in the Amazon will gather at the surface near the point where a urine stream enters, having been attracted by the noise and agitation of the water.
In 1836 Eduard Poeppig documented a statement by a local physician in Pará
, known only as Dr. Lacerda, who offered an eyewitness account of a case where a candiru had entered a human orifice. However, it was lodged in a native woman's vagina, rather than a male urethra. He relates that the fish was extracted after external and internal application of the juice from a Xagua plant (believed to be a name for Genipa americana
). Another account was documented by biologist George A. Boulenger from a Brazilian physician named Dr. Bach, who examined a man and several boys whose penises had been amputated. Bach believed this was a remedy performed because of parasitism by candiru, but he was merely speculating as he did not speak his patients' language. American biologist Eugene Willis Gudger noted the area the patients were from did not have candiru in its rivers, and suggested the amputations were much more likely the result of having been attacked by piranha.
In 1891, naturalist Paul Le Cointe provides a rare first-hand account of a candiru entering a human body, and like Lacerda's account, it involved the fish being lodged in the vaginal canal, not the urethra. Le Cointe actually removed the fish himself, by pushing it forward to disengage the spines, turning it around and removing it head-first.
Gudger, in 1930, noted there have been several other cases reported wherein the fish entered the vaginal canal, but not a single case of a candiru entering the anus was ever documented. According to Gudger, this lends credence to the unlikelihood of the fish entering the male urethra, based on the comparatively small opening that would only accommodate the most immature members of the species.
It was also once thought that the fish was attracted to urine, as the candiru's primary prey emits urea
from its gills, but this was later discredited in formal experimentation. Indeed, the fish appears not to have any response to any chemical attractants, and primarily hunts by visual tracking.
, Brazil
in 1997. In this incident, the victim (a 23 year old man known only as "F.B.C.") claimed a candiru "jumped" from the water into his urethra as he urinated while thigh-deep in a river. After traveling to Manaus
on October 28, 1997, the victim underwent a two-hour urological
surgery by Dr. Anoar Samad to remove the fish from his body.
In 1999, American marine biologist Stephen Spotte traveled to Brazil to investigate this particular incident in detail. He recounts the events of his investigation in his book Candiru: Life and Legend of the Bloodsucking Catfishes. Spotte met with Dr. Samad in person and interviewed him at his practice and home. Samad gave him photos, the original VHS tape of the cystoscopy
procedure, and the actual fish's body preserved in formalin as his donation to the INPA. Spotte and his colleague Paulo Petry took these materials and examined them at the INPA, comparing them with Samad's formal paper. While Spotte did not overtly express any conclusions as to the veracity of the incident, he did remark on several observations that were suspicious about the claims of the patient and/or Samad himself.
wrote about the candiru in his 1959 novel Naked Lunch
, describing it as "a small eel-like fish or worm about one-quarter inch through and two inches long patronizing certain rivers of ill repute in the Greater Amazon Basin, will dart up your prick or your arsehole or a woman's cunt faute de mieux, and hold himself there by sharp spines with precisely what motives is not known since no one has stepped forward to observe the candiru's life-cycle in situ". Burroughs also mentioned it in The Yage Letters
: "At that time I was stationed at the remote jungle outpost of Candiru, so named from a tiny eel like fish that infests the rivers of that area. This vicious fish introduces itself into the most intimate parts of the human body, maintaining itself there by poisonous barbs while it feeds on the soft membranes".
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
), also known as cañero, toothpick fish, or vampire fish, are a number of genera of parasitic freshwater
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
catfish
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Trichomycteridae
Trichomycteridae
Trichomycteridae is a family of catfishes commonly known as the pencil or parasitic catfishes. This family includes the infamous candiru fish, feared by some people for its alleged habit of entering into the urethra of humans....
; all are native to the Amazon River
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
. Although some candiru species have been known to grow to a size of 16 inches (~41 cm) in length, others are considerably smaller. These smaller species are known for an alleged tendency to invade and parasitise the human urethra
Urethra
In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...
; however, despite ethnological reports dating back to the late 19th century, the first documented case of the removal of a candiru from a human urethra did not occur until 1997, and even that incident has remained a matter of controversy.
The definition of candiru differs between authors. The word has been used to refer to only Vandellia cirrhosa, the entire genus Vandellia
Vandellia
Vandellia is a genus of catfishes of the family Trichomycteridae. It includes three species, V. beccarii, V. cirrhosa, and V. sanguinea. Vandellia is the most well-known genus of parasitic catfishes also known as candiru, known for their alleged habit of entering the human urethra.-Distribution:V...
, the subfamily Vandelliinae
Vandelliinae
The Vandelliinae are a subfamily of catfishes of the family Trichomycteridae. Vandelliines are hematophagous, feeding on the blood of larger fish...
, or even the two subfamilies Vandelliinae and Stegophilinae
Stegophilinae
Stegophilinae is a subfamily of catfishes of the family Trichomycteridae.It includes twelve genera, Acanthopoma, Apomatoceros, Haemomaster, Henonemus, Homodiaetus, Megalocentor, Ochmacanthus, Parastegophilus, Pareiodon, Pseudostegophilus, Schultzichthys, and Stegophilus...
.
Physical description
Candirus are small fish. Adults can grow to around 15 cm with a rather small head and a belly that can appear distended, especially after a large blood meal. The body is translucent making it quite difficult to spot in the turbid waters of its home. There are short sensory barbels around the head, together with short, backward pointing spines on the gill covers.Location and habitat
Candirus (VandelliaVandellia
Vandellia is a genus of catfishes of the family Trichomycteridae. It includes three species, V. beccarii, V. cirrhosa, and V. sanguinea. Vandellia is the most well-known genus of parasitic catfishes also known as candiru, known for their alleged habit of entering the human urethra.-Distribution:V...
) inhabit the Amazon
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
and Orinoco
Orinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
rivers of lowland Amazonia, where they constitute part of the Neotropical fish
Neotropical fishes
The freshwater fishes of tropical South and Central America represent one of the most diverse aquatic ecosystems on Earth, with more than 5,600 species, representing about 10% all living vertebrate species...
fauna. Candirus are hematophagous and parasitize the gills of larger Amazonian fishes, especially catfishes of the family Pimelodidae
Pimelodidae
Pimelodidae, commonly known as the long-whiskered catfishes, is a family of catfishes .-Taxonomy:Pimelodidae has undergone much revision. Currently, the family contains about 30 genera and about 90 recognized and known but unnamed species...
(Siluriformes).
Attacks on humans: myth vs. fact
Although lurid anecdotesAnecdotal evidence
The expression anecdotal evidence refers to evidence from anecdotes. Because of the small sample, there is a larger chance that it may be true but unreliable due to cherry-picked or otherwise unrepresentative of typical cases....
of attacks on humans abound, very few cases have been verified, and some alleged traits of the fish have been discredited as myth or superstition.
Historical accounts
The earliest published report on this candiru attacking human hosts comes from German biologist C. F. P. von MartiusCarl Friedrich Philipp von Martius
Carl Friedrich Philipp von Martius was a German botanist and explorer.Martius was born at Erlangen, where he graduated M.D. in 1814, publishing as his thesis a critical catalogue of plants in the botanic garden of the university...
in 1829, who never actually observed it, but rather was told about it by the native people of the area, including that men would tie a ligature around their penis while going into the river to prevent this from happening. Other sources also suggest that other tribes in the area used various forms of protective coverings for their genitals while bathing, though it was also suggested that these were to prevent bites from piranha. Martius also speculated that the fish were attracted by the "odor" of urine. Later experimental evidence showed this to be false, as the fish actually hunt by sight and have no attraction to urine at all.
Another report from French naturalist Frances de Castelnau in 1855 relates an allegation by local Araguay fisherman, saying that it is dangerous to urinate in the river as the fish "springs out of the water and penetrates into the urethra by ascending the length of the liquid column." While Castelnau himself dismissed this claim as "absolutely preposterous," and the fluid mechanics
Fluid mechanics
Fluid mechanics is the study of fluids and the forces on them. Fluid mechanics can be divided into fluid statics, the study of fluids at rest; fluid kinematics, the study of fluids in motion; and fluid dynamics, the study of the effect of forces on fluid motion...
of such a thing occurring literally defy the laws of physics, it remains one of the more stubborn myths about the candiru. It has been suggested this claim evolved out of the real observation that certain species of fish in the Amazon will gather at the surface near the point where a urine stream enters, having been attracted by the noise and agitation of the water.
In 1836 Eduard Poeppig documented a statement by a local physician in Pará
Pará
Pará is a state in the north of Brazil. It borders the Brazilian states of Amapá, Maranhão, Tocantins, Mato Grosso, Amazonas and Roraima. To the northwest it also borders Guyana and Suriname, and to the northeast it borders the Atlantic Ocean. The capital is Belém.Pará is the most populous state...
, known only as Dr. Lacerda, who offered an eyewitness account of a case where a candiru had entered a human orifice. However, it was lodged in a native woman's vagina, rather than a male urethra. He relates that the fish was extracted after external and internal application of the juice from a Xagua plant (believed to be a name for Genipa americana
Genipa americana
Genipa americana is a species of Genipa, native to northern South America , the Caribbean and southern Mexico, growing in rainforests. It is commonly called Genipapo or Huito; the alternate name Jagua may refer to other species of Genipa as well. To the Inca, it was known as hawa or wituq...
). Another account was documented by biologist George A. Boulenger from a Brazilian physician named Dr. Bach, who examined a man and several boys whose penises had been amputated. Bach believed this was a remedy performed because of parasitism by candiru, but he was merely speculating as he did not speak his patients' language. American biologist Eugene Willis Gudger noted the area the patients were from did not have candiru in its rivers, and suggested the amputations were much more likely the result of having been attacked by piranha.
In 1891, naturalist Paul Le Cointe provides a rare first-hand account of a candiru entering a human body, and like Lacerda's account, it involved the fish being lodged in the vaginal canal, not the urethra. Le Cointe actually removed the fish himself, by pushing it forward to disengage the spines, turning it around and removing it head-first.
Gudger, in 1930, noted there have been several other cases reported wherein the fish entered the vaginal canal, but not a single case of a candiru entering the anus was ever documented. According to Gudger, this lends credence to the unlikelihood of the fish entering the male urethra, based on the comparatively small opening that would only accommodate the most immature members of the species.
It was also once thought that the fish was attracted to urine, as the candiru's primary prey emits urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....
from its gills, but this was later discredited in formal experimentation. Indeed, the fish appears not to have any response to any chemical attractants, and primarily hunts by visual tracking.
Modern case
To date, there is only one documented case of a candiru entering a human urinary system, which took place in ItacoatiaraItacoatiara
Itacoatiara is one of the 48 official neighborhoods into which the city of Niterói, Rio de Janeiro in Brazil is divided.- Beach :Itacoatiara beach is located about 30 minutes east of downtown Niterói by car, or one hour by bus....
, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
in 1997. In this incident, the victim (a 23 year old man known only as "F.B.C.") claimed a candiru "jumped" from the water into his urethra as he urinated while thigh-deep in a river. After traveling to Manaus
Manaus
Manaus is a city in Brazil, the capital of the state of Amazonas. It is situated at the confluence of the Negro and Solimões rivers. It is the most populous city of Amazonas, according to the statistics of Brazilian Institute of Geography and Statistics, and is a popular ecotourist destination....
on October 28, 1997, the victim underwent a two-hour urological
Urology
Urology is the medical and surgical specialty that focuses on the urinary tracts of males and females, and on the reproductive system of males. Medical professionals specializing in the field of urology are called urologists and are trained to diagnose, treat, and manage patients with urological...
surgery by Dr. Anoar Samad to remove the fish from his body.
In 1999, American marine biologist Stephen Spotte traveled to Brazil to investigate this particular incident in detail. He recounts the events of his investigation in his book Candiru: Life and Legend of the Bloodsucking Catfishes. Spotte met with Dr. Samad in person and interviewed him at his practice and home. Samad gave him photos, the original VHS tape of the cystoscopy
Cystoscopy
Cystoscopy is endoscopy of the urinary bladder via the urethra. It is carried out with a cystoscope.Diagnostic cystoscopy is usually carried out with local anaesthesia...
procedure, and the actual fish's body preserved in formalin as his donation to the INPA. Spotte and his colleague Paulo Petry took these materials and examined them at the INPA, comparing them with Samad's formal paper. While Spotte did not overtly express any conclusions as to the veracity of the incident, he did remark on several observations that were suspicious about the claims of the patient and/or Samad himself.
- According to Samad, the patient claimed "the fish had darted out of the water, up the urine stream, and into his urethra." While this is the most popularly known legendary trait of the candiru, according to Spotte it has been known conclusively to be a myth for more than a century, as it is impossible due to simple fluid physics.
- The documentation and specimen provided indicate a fish that was 133.5 mm in length and had a head with a diameter of 11.5 mm. This would have required significant force to pry the urethra open to this extent. The candiru has no appendages or other apparatus that would have been necessary to accomplish this, and if it were leaping out of the water as the patient claimed, it would not have had sufficient leverage to force its way inside.
- Samad's paper claims the fish must have been attracted by the urine. This belief about the fish has been around for centuries, but was discredited in 2001. While this was merely speculation on Samad's part based on the prevailing scientific knowledge at the time, it somewhat erodes the patient's story by eliminating the motivation for the fish to have attacked him in the first place.
- Samad claimed the fish had "chewed" its way through the ventral wall of the urethra into the patient's scrotum. Spotte notes that the candiru does not possess the right teeth or strong enough dentition to have been capable of this.
- Samad claimed he had to snip the candiru's grasping spikes off in order to extract it, yet the specimen provided had all its spikes intact.
- The cystoscopy video depicts traveling into to a tubular space (presumed to be the patient's urethra) containing the fish's carcass and then pulling it out backwards through the urethral opening, something that would have been almost impossible with the fish's spikes intact.
In literature
William S. BurroughsWilliam S. Burroughs
William Seward Burroughs II was an American novelist, poet, essayist and spoken word performer. A primary figure of the Beat Generation and a major postmodernist author, he is considered to be "one of the most politically trenchant, culturally influential, and innovative artists of the 20th...
wrote about the candiru in his 1959 novel Naked Lunch
Naked Lunch
Naked Lunch is a novel by William S. Burroughs originally published in 1959. The book is structured as a series of loosely-connected vignettes. Burroughs stated that the chapters are intended to be read in any order...
, describing it as "a small eel-like fish or worm about one-quarter inch through and two inches long patronizing certain rivers of ill repute in the Greater Amazon Basin, will dart up your prick or your arsehole or a woman's cunt faute de mieux, and hold himself there by sharp spines with precisely what motives is not known since no one has stepped forward to observe the candiru's life-cycle in situ". Burroughs also mentioned it in The Yage Letters
The Yage Letters
The Yage Letters, first published in 1963, is a collection of correspondence and other writings by Beat Generation authors William S. Burroughs and Allen Ginsberg...
: "At that time I was stationed at the remote jungle outpost of Candiru, so named from a tiny eel like fish that infests the rivers of that area. This vicious fish introduces itself into the most intimate parts of the human body, maintaining itself there by poisonous barbs while it feeds on the soft membranes".