- Channidae
Taxobox
name = Snakehead
image_width = 250px
image_caption =Northern snakehead , "Channa argus"
regnum =Animal ia
phylum =Chordata
classis =Actinopterygii
ordo =Perciformes
subordo=Channoidei
familia = Channidae
subdivision_ranks = Genera
subdivision = "Channa " "Eochanna " "Parachanna "Channidae is a family of
freshwater fish commonly known as snakeheads, and is native toAfrica andAsia . There are twoextant genera , "Channa " in Asia, and "Parachanna " in Africa, consisting of 30-35 species. Thesepredator y fishes are distinguished by a longdorsal fin , small head with large head scales on top, large mouth and teeth. They have a physiological need to breathe atmospheric air, which they do with asuprabranchial organ : a primitive form of alabyrinth organ .They are considered valuable food fish. Larger species like "
Channa striata ", "Channa maculata " or "Parachanna obscura " are farmed inaquaculture . Snakeheads feed onplankton , aquaticinsect s, andmollusk s when small. When adult, they mostly feed on other fish like carp, orfrog s. In rare cases, smallmammal s such asrat s are taken. The size of the snakehead species differs greatly. "Dwarf snakeheads" like "Channa gachua " grow to 10inch es (25 cm). Most snakeheads grow up to 2 or 3 ft. (60–100 cm). Only two species ("Channa marulius " and "Channa micropeltes") can reach a length of more than 1 meter and a weight of more than 6 kg.It is illegal to keep snakeheads as pets in thirteen states of the USA and other countries as they have become an
invasive species due to irresponsible owners releasing them into the wild when they could/would no longer take care of them. If in an enclosed area they will try anything to escape. If in anaquarium they will charge at full force and tend to knock over the aquarium or shatter the glass.Fact|date=March 2008Channidae is also known as the the Northern Snakehead, or Channa Argus, and is native to Asia. There are 29 known Snakehead varieties.Fact|date=July 2008'They can travel across land and live out of water for up to three days,' [says U.S. Secretary of the Interior
Gale Norton ] .[Snakeheads can breathe air unlike other fish as they] use a primitive lung above their gills... [or] 'air chambers'.
Out of the water Snakeheads rhythmically move their fins and muscular bodies back and forth: the fish equivalent of walking... It's a resourceful adaptation. [In their native Asia they must survive both wet and dry weather cycles like monsoons and droughts.]
When the Snakehead eats it is a thrust predator. It will eat its prey all at once, striking and ingesting it whole.Fact|date=July 2008
The Giant Snakehead, or Channa micropeltes, is native throughout Asia, and is the most aggressive Snakehead. They can grow to over 1.5 metres long. Adult Snakeheads force their hatchlings to breathe air by pushing them to the surface.
From 2002 to 2003, one Los Angeles supermarket was found to have sold approximately 25,000 dollars worth of illegal live Snakeheads which caused breakouts in local eco systems.
It has had recent sightings in Lincolnshire (UK) (which proved to be hoax) and in the U.S. National Geographic referred to it as "Fishzilla".cite web |url=http://natgeowild.co.uk/explore/Fishzilla/ |title=Fishzilla |work=Nat Geo Wild |publisher=NGC-UK Partnership] cite web |url=http://ngcblog.nationalgeographic.com/ngcblog/2007/12/snakehead_frenzy.html |title=Snakehead Frenzy! |work=NGC Blog |publisher=
National Geographic Channel |date=2007-12-03 |first=Elena |last=Cruz]pecies
[
Courtenay, Jr., Walter R. and James D. Williams. [http://fisc.er.usgs.gov/Snakehead_circ_1251/html/index.html USGS Circular 1251: Snakeheads (Pisces, Chinnidae) - A Biological Synopsis and Risk Assessment. U.S. Department of the Interior, U.S. Geological Survey] .
2004 -04-01 . Retrieved2007 -07-16 .] ] There are about 30-35 species in two genera:
* Genus "Channa "
**Borna snakehead , "Channa amphibeus " (McClelland, 1845).
**Northern snakehead , "Channa argus " (Cantor, 1842).
** "Channa asiatica " (Linnaeus, 1758).
** "Channa aurantimaculata " Musikasinthorn, 2000.
** "Channa bankanensis " (Bleeker, 1852).
**Barca snakehead , "Channa barca " (Hamilton, 1822).
**Rainbow snakehead , "Channa bleheri " Vierke, 1991.
** "Channa burmanica " Chaudhuri, 1916.
** "Channa cyanospilos " (Bleeker, 1853).
** "Channa gachua " (Hamilton, 1822).
** "Channa harcourtbutleri " (Annandale, 1918).
**Forest snakehead , "Channa lucius " (Cuvier, 1831).
** "Channa maculata " (Lacépède, 1801).
** "Channa marulioides " (Bleeker, 1851).
**Great snakehead , "Channa marulius " (Hamilton, 1822).
** "Channa melanoptera " (Bleeker, 1855).
**Black snakehead , "Channa melasoma " (Bleeker, 1851).
**Giant snakehead , "Channa micropeltes " (Cuvier, 1831).
** "Channa nox " Zhang, Musikasinthorn & Watanabe, 2002.
**Walking snakehead , "Channa orientalis " Bloch & Schneider, 1801.
** "Channa ornatipinnis " Britz, 2007.cite journal | journal = Ichthyological Exploration of Freshwaters | volume = 18 | issue = 4 | year = 2007 | pages = 335–344 | title = "Channa ornatipinnis" and "C. pulchra", two new species of dwarf snakeheads from Myanmar (Teleostei: Channidae) | author = Britz, Ralf]
** "Channa panaw " Musikasinthorn, 1998.
** "Channa pleurophthalmus " (Bleeker, 1851).
** "Channa pulchra " Britz, 2007.
**Spotted snakehead , "Channa punctata " (Bloch, 1793).
**Assamese snakehead , "Channa stewartii " (Playfair, 1867).
**Snakehead murrel , "Channa striata " (Bloch, 1793).
* Genus "Eochanna "
** "Eochanna chorlakkiensis (Roe , 1991).
* Genus "Parachanna "
** "Parachanna africana " (Steindachner, 1879).
** "Parachanna insignis " (Sauvage, 1884).
** †"Parachanna fayumensis " Murray, 2006. (fossil )
**Obscure snakehead , "Parachanna obscura " (Günther, 1861).Prehistory and evolution
Channidae are well-represented in the fossil record and known from numerous specimens. Research indicates that snakeheads likely originated in the south Himalayan region (modern-day
Pakistan ) at least 50 million years ago, during the Early Eocene epoch. By 17 Ma, during the Early Miocene, Channidae had spread into western and central Eurasia, and by 8 Ma, during the lateTortonian , they could be found throughout Africa and East Asia. cite journal |last=Böhme |first=Madelaine |year=2004 |month=May |title=Migration history of air-breathing fishes reveals Neogene atmospheric circulation patterns |journal=Geology |volume=32 |issue=5 |pages=393–396 |url=http://www.gsajournals.org/perlserv/?request=get-abstract&doi=10.1130%2FG20316.1 |accessdate=2008-07-09] As Channidae are adapted to climates of high precipitation with mean temperatures of 20 °C (68 °F), their migrations into Europe and Asia correspond to the development of theIntertropical Convergence Zone , which increased air humidity, and the intensification of theEast Asian monsoon , respectively. Both weather patterns emerged due to greater vertical growth of theAlps ,Pyrenees , andHimalayas , which affected Eurasian climactic patterns. cite journal |last=Böhme |first=Madelaine |year=2004 |month=May |title=Migration history of air-breathing fishes reveals Neogene atmospheric circulation patterns |journal=Geology |volume=32 |issue=5 |pages=393–396 |url=http://www.gsajournals.org/perlserv/?request=get-abstract&doi=10.1130%2FG20316.1 |accessdate=2008-07-09]Ecological concerns
Snakeheads can become
invasive species and causeecological damage because they are top-level predators, meaning that they have no natural enemies outside of their native environment. Not only can they breathe atmospheric air, but they can also survive on land for up to four days, provided they are wet, and are known to migrate on wet land to other bodies of water by wriggling with their body and fins.Snakeheads became a national news topic in the US because of the appearance of
northern snakehead s spawning in aMaryland pond in 2002. [http://news.nationalgeographic.com/news/2002/07/0702_020702_snakehead.html Maryland Wages War on Invasive Walking Fish] Hillary Mayell. "National Geographic ",02 July 2002 .] Northern snakeheads became permanently established in thePotomac River around 2004, [http://www.baltimoresun.com/sports/outdoors/bal-md.snakeheads27apr27,0,6241227.story Potomac snakeheads not related to others] Associated Press, "Baltimore Sun",27 April 2007 .] and possibly established inFlorida . Apparently non-established specimens have been found in Flushing Meadows-Corona Park,New York , as well asWawayanda, New York [cite news|url=http://www.recordonline.com/apps/pbcs.dll/article?AID=/20080806/NEWS/808060331|title=DEC sprays poison to kill snakeheads|publisher="The Times Herald Record "|date=August 6 ,2008 |author=Yakin, Heather] , two ponds outsidePhiladelphia ,Pennsylvania a pond inMassachusetts , and reservoirs inCalifornia andNorth Carolina .They are prohibited in several other countries,Fact|date=July 2007 like
Australia , because their introduction to new ecosystems may displace indigenous species. Humans have been introducing snakeheads to non-indigenous waters for over 100 years. In parts of Asia and Africa, the snakehead is considered a valuable food fish and is produced in aquacultures. Due to this fact it was introduced either on purpose (fisheries motivation) or by ignorance (as was the case in Crofton).Some examples of the introduction of snakeheads to non-indigeneous waters include:
* "Channa maculata " was introduced toMadagascar and toHawaii around the end of the 19th century. It can still be found there today.
* "Channa striata " was introduced to islands east of theWallace line by governmental programs in the later half of the 20th century. InFiji , the introduction failed.
* "Channa asiatica ", which is native to southern China, was introduced toTaiwan and to southernJapan . In this case the origin and reason of the introduction is unknown, but most probably due to human intervention.
* "Channa argus ", which is native to northern China (Amur River), was introduced to Central Asia (Kazakhstan ,Turkmenistan ,Uzbekistan ). It was introduced toJapan about 100 years ago due to fisheries motivations. Its introduction toCzechoslovakia by the government in the 1960s failed due to cold winters.A comprehensive work on the dangers of the introduction of snakeheads to non-indigeneous waters is [http://cars.er.usgs.gov/circ_1251_courtenay.pdf that of Prof. W. Courtenay] .Other Sightings in the U.S.
In what was determined by the Army Corps of Engineers to be an cite web |url=http://abclocal.go.com/wls/story?section=News&id=2277918&ft=med |title=isolated incident , a fisherman caught a single snakehead on
October 9 ,2004 while fishing fromLake Michigan at Burnham Harbor in Chicago,Illinois . Snakeheads have also been spotted inAlabama ,Arkansas ,California ,Colorado ,Florida ,Maryland , Georgia,Hawaii ,Idaho ,Kentucky ,Mississippi ,New York ,Nevada ,North Carolina ,Oregon ,Pennsylvania ,South Carolina ,Texas ,Utah ,Wisconsin , andWashington . cite news
first = Jeffrey
last = Kluger
title = Fish Tale
url = http://www.time.com/time/magazine/article/0,9171,1002979-1,00.html
work = Time Magazine
date = 2002-08-05
accessdate = 2008-02-22 ] [http://www.epa.gov/EPA-IMPACT/2002/October/Day-04/i25337.htm Injurious Wildlife Species; Snakeheads] Environmental Protection Agency. Retrieved17 February 2008 .]ightings in the UK
On
February 19 ,2008 it was reported that a snakehead weighing almost lb to kg|num=3|precision=1 was caught in the River Witham nearNorth Hykeham ,Lincolnshire . The "Angler's Mail " confirmed it was a giant snakehead "Channa micropeltes ". [cite news
first = Paul
last = Stokes
title = Fish that attacks people caught in Witham
url = http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/02/20/eafish120.xml
work = Telegraph
date = 2008-02-20
accessdate = 2008-02-22 ] [cite news
first = Jeffrey
last = Kluger
title = Man-eating 'psycho' fish found in UK
url = http://www.metro.co.uk/news/article.html?in_article_id=100114&in_page_id=34
work = Metro.co.uk
publisher = Associated Newspapers
date = 2008-02-19
accessdate = 2008-02-22 ] This subsequently turned out to be ahoax . [cite journal|last=Clarke|first=Matt|title=Snakehead catch 'a hoax'|journal=Practical Fishkeeping|date=April 2008] The "Norfolk Eastern Daily Press" reported in March: [cite news
url = http://new.edp24.co.uk/content/sport/story.aspx?brand=EDPOnline&category=Sport&tBrand=EDPOnline&tCategory=Sport&itemid=NOED04%20Mar%202008%2020%3A36%3A20%3A940
title = Picture perfect haul delights Harris
first= Roy | last= Webster
work= Norfolk Eastern Daily Press
date = 2008-03-05
accessdate = 2008-04-01 ] quote|Expert opinion from fish scientists insisted this warm water species could never survive in the icy Lincolnshire river for more than a few seconds. It has since been discovered the snakehead was actually dead laying in a Lincoln street and the finder preserved it in a domestic freezer until the following weekend when the misleading pictures were taken.Removal
Snakeheads may be exterminated by applying the
herbicide sdiquat dibromide andglyphosate (tradenames such asRoundup , Rodeo) to ponds to eliminate aquatic vegetation. The death of aquatic plants causes dissolved oxygen levels to drop, and a subsequent fish kill occurs.Fact|date=July 2007Approximately one to two weeks after the application of the herbicides, application of the
piscicide Rotenone kills any remaining fish. Dead fish should be removed daily; however, unpleasant odors from decaying organic material are to be expected.Notes
References
*
*External links
* [http://fishing.about.com/cs/fishfactsinfo/a/aa092703a.htm About.com's article on Snakeheads]
* [http://www.snakeheads.org snakeheads.org] world's largest website for snakeheads
* [http://www.scinet.cc/articles/northern-snakehead/frankenfish.html Overview of Northern Snakehead biology]
* [http://www.biodiversitypartners.org/state/fl/snakehead.shtml Student article on Snakehead problem in Florida]
* [http://www.mauricemartin.net/snakehead.htm Fish or Foul: Snakeheads near Washington, D.C., and the people who love them]
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