Candiru
From Wikipedia, the free encyclopedia
| Candiru | |
|---|---|
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| Vandellia cirrhosa | |
| Conservation status | |
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Secure
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| 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 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 6 inches (~15 cm) in length, others are considerably smaller. These smaller species are known for an alleged tendency to invade and parasitize the human urethra; however, despite ethnological reports dating back to the late 19th century,[1] the first documented case of a candiru parasitizing a human did not occur until 1997.
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]
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[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] Alleged attacks on people
Although lurid anecdotes of attacks of humans abound, there is only one documented case of a candiru entering a human orifice.[7] One popular myth was that the fish was capable of swimming up a man's urine stream in mid-air to enter the urethra, though this is actually impossible. Nonetheless, there was a case in which the victim claimed that the fish "jumped" into his urethra while he was urinating thigh deep in a river.[8] It was also once thought that the fish was attracted to urine, but this was later discredited in formal experimentation.[4][9] Indeed, the fish appears to not have any response to any chemical attractants, and primarily hunts by visual tracking.[9] Bathers in the region are, however, warned not to urinate while swimming, as the expansion of the urethra during urination appears to be what allows the fish to enter the otherwise closed orifice.[8]
A traditional treatment for those affected 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]
Surgery to the affected region is the medical standard of care for those who have been attacked. [11][12]
[edit] References
- ^ Ricciuti, Edward R.; Bird, Jonathan (2003). Killers of the Seas: The Dangerous Creatures That Threaten Man in an Alien Environment. The Lyons Press. ISBN 978-1585748693.
- ^ "Vandellia cirrhosa". FishBase. Ed. Ranier Froese and Daniel Pauly. July 2007 version. N.p.: FishBase, 2007.
- ^ Breault, J.L.. "Candiru: Amazonian parasitic catfish". Journal of Wilderness Medicine 2 (4): 304–312. http://www.wemjournal.org/wmsonline/?request=get-abstract&issn=0953-9859&volume=002&issue=04&page=0304.
- ^ a b de Carvalho, Marcelo R. (2003). "Analyse D’Ouvrage" (PDF). Cybium 27 (2): 82. http://www.mnhn.fr/sfi/cybium/numeros/pdf/272pdf/01.analysecarvalho.pdf. Retrieved 2009-06-22.
- ^ 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:.
- ^ Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
- ^ "this was the only documented evidence of an accident involving humans." Anoar Samad, "Candiru inside the urethra" http://google.com/translate?u=http%3A%2F%2Fweb.archive.org%2Fweb%2F20040616043555%2Fhttp%3A%2F%2Fwww.internext.com.br%2Furologia%2FCasosclinicos.htm&langpair=pt%7Cen&hl=en&ie=UTF8
- ^ a b "Can the candiru fish swim upstream into your urethra (revisited)?". The Straight Dope. 07-September 2001. http://www.straightdope.com/columns/010907.html.
- ^ a b Spotte, Stephen; Petry, Paulo; Zuanon, Jansen A.S. (2001). "Experiments on the feeding behavior of the hematophagous candiru.". Environmental Biology of Fishes 60: 459–464. doi:.
- ^ "Can the candiru fish swim upstream into your urethra?". The Straight Dope. 19-May 2000. http://www.straightdope.com/columns/000519.html.
- ^ Article on removal of candiru from a male patient with pictures
- ^ Youtube Video of Animal Planet documentary detailing infestation by and surgical removal of candiru from penis
