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Vandellia cirrhosa
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Superfamily: Loricarioidea
Family: Trichomycteridae
Bleeker, 1858

Candiru (English and Portuguese) or candirú (Spanish), also known as canero or toothpick fish, are parasitic freshwater catfish of a number of genera in the family Trichomycteridae. They are found in the Amazon River and have a reputation among the natives as the most feared fish in its waters, even over piranha.[1] They are eel-shaped and translucent, making them almost impossible to see in the water. Some species have been known to grow to a size of 6 inches (~15 cm) in length.

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.[2][3][4][5]


[edit] 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.[6]

[edit] Location and habitat

The area most populated by this fish is at the junction of the Amazon River and the Rio Negro, near Brazil's inland city of Manaus. Here they thrive as the low pH, brown, largely organic-material based Amazon river churns with the conversely high pH (basic), oligotrophic (with very low nutrient content, i.e., organic material), tannin-saturated flows of the Rio Negro. This mixing point provides a rich diversity of sustained fauna.

[edit] Parasitism

Candiru are parasites. Their ability to detect respiratory currents in the water allows them to swim into the gill openings of other aquatic species, where they feed on their prey's blood.

While the members of the subfamily Vandelliinae feed on blood, members of Stegophilinae may feed on scales, mucus, or carrion.[7]

The Candirú lies in wait at the river's murky bottom, searching for its next host by sampling/sniffing the water for expelled chemicals, such as urea and ammonia from the gills of other fish. Once having detected a fish in the vicinity, with a burst of speed the Candirú darts towards the gill cavity and lodges itself in place with its spines. Then, with usually fatal consequences for its victim, the Candirú begins to gnaw a hole towards a major blood vessel and gorges itself for no more than a few minutes. It will then dislodge itself and sink back to the river bed in order to digest its food and wait for its next meal.

[edit] Alleged attacks on people

Although lurid anecdotes of attacks of humans abound (see Popular Culture section below), there is only one documented case of a candiru attack on a human.[8]A well-circulated myth is that the candiru is capable of swimming up the stream of urine in mid-air to a victim standing on shore or a boat. Nonetheless, there was a case in which the victim claimed that the fish jumped while he was urinating thigh deep.[9] They are also probably not attracted to pure urine.[4] It is believed that they are able to enter a human urethra only when it is expanded during urination.[9]

A traditional "cure" involves the use of two plants, the jagua or jenipapo plant (Genipa americana) and the Buitach apple which are inserted (or their extract in the case of tight spaces) into the affected area. It is thought that these two plants together will kill and then dislodge the fish.[10]

[edit] Popular culture

[edit] References

  1. ^ Axelrod, Herbert R.; Emmens, C.; Burgess, W.;Pronek, N. (1996). Exotic Tropical Fishes. T.F.H. Publications. ISBN 0-87666-543-1. 
  2. ^ "Vandellia cirrhosa". FishBase. Ed. Ranier Froese and Daniel Pauly. July 2007 version. N.p.: FishBase, 2007.
  3. ^ Breault, J.L.. "Candiru: Amazonian parasitic catfish". Journal of Wilderness Medicine 2 (4): 304–312. 
  4. ^ a b de Carvalho, Marcelo R. (2003). "Analyse D’Ouvrage" (PDF). Cybium 27 (2): 82. 
  5. ^ DoNascimiento, Carlos; Provenzano, Francisco (2006). "The Genus Henonemus (Siluriformes: Trichomycteridae) with a Description of a New Species from Venezuela". Copeia 2006 (2): 198–205. doi:10.1643/0045-8511(2006)6[198:TGHSTW]2.0.CO;2. 
  6. ^ Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
  7. ^ Schaefer, Scott A.; Provenzano, Francisco; de Pinna, Mario; Baskin, Jonathan N. (2005-11-29). "New and Noteworthy Venezuelan Glanapterygine Catfishes (Siluriformes, Trichomycteridae), with Discussion of Their Biogeography and Psammophily" (PDF). American Museum Novitates 496 (3496): 1–27. doi:10.1206/0003-0082(2005)496[0001:NANVGC]2.0.CO;2. 
  8. ^ "this was the only documented evidence of an accident involving humans." Anoar Samad, "Candiru inside the urethra"
  9. ^ a b "Can the candiru fish swim upstream into your urethra (revisited)?". The Straight Dope. 07-September 2001. 
  10. ^ "Can the candiru fish swim upstream into your urethra?". The Straight Dope. 19-May 2000. 
  11. ^ Kirschling, Gregory (2007-04-27). "A Perfect Day for Penisfish". Entertainment Weekly.,,20037051,00.html. Retrieved on 2007-05-17. 
  12. ^ Dicionário Houaiss da Língua Portuguesa. Rio de Janeiro: Editora Objetiva. 2007. ISBN 857302383X. 

[edit] External links

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