Snakehead (fish)

{{Short description|Family of fishes}} {{Other uses|Snakehead (disambiguation)}} {{distinguish|Chanidae}} {{Automatic taxobox | fossil_range = Eocene to recent, {{fossil range|48.6|0}} | image = Snakehead - Channa argus 2.jpg | image_caption = Northern snakehead, ''Channa argus'' | taxon = Channidae | authority = Fowler, 1934 | subdivision_ranks = Genera | subdivision = See text }}

The '''snakeheads''' are members of the freshwater perciform fish family '''Channidae''', native to parts of Africa and Asia. These elongated, predatory fish are distinguished by their long dorsal fins, large mouths, and shiny teeth. They breathe air with gills, which allows them to migrate short distances over land. They have suprabranchial organs, which are primitive forms of labyrinth organs, that develop when they grow older.<ref>Pinter, H. (1986). ''Labyrinth Fish.'' Barron's Educational Series, Inc., {{ISBN|0-8120-5635-3}}.</ref> The two extant genera are ''Channa'' in Asia and ''Parachanna'' in Africa, consisting of more than 50 species.

They are valuable as a food source and have become notorious as an intentionally released invasive species. These fish have been kept as pets, but as they get larger, people let them go into ponds, lakes, and rivers, making these fish invasive.

==Description== The various species of snakeheads differ greatly in size; dwarf snakeheads, such as ''Channa orientalis'', do not surpass {{convert|25|cm|abbr=on|0}} in length. Most other snakeheads reach between {{convert|30|and|90|cm|abbr=on}}. Five species (''C. argus'', ''C. barca'', ''C. marulius'', ''C. micropeltes'', and ''C. striata'') can reach {{convert|1.0|m|abbr=on}} or more.<ref>{{FishBase genus | genus=Channa | month=June | year= 2014}}</ref>

Snakeheads are thrust-feeders{{Clarify|reason=what is a "thrust-feeder"?|date=December 2024}} that consume plankton, aquatic insects, and mollusks when small. As adults, they mostly feed on other fish (such as carp) or on frogs. In rare cases, small rodents such as rats are eaten.

==History== The Channidae are well represented in the fossil record and known from numerous specimens. They likely originated in the south Himalayan region of the Indian subcontinent (modern-day northern India and eastern Pakistan) at least 50 million years ago (Mya), during the Early Eocene epoch. Two of the earliest known species, ''Eochanna chorlakkiensis''  and ''Anchichanna kuldanensis'' , have both been found in the Middle Eocene of Pakistan.<ref name=Murray2008>{{cite journal |doi=10.1671/0272-4634(2008)28[41:EAFFPW]2.0.CO;2 |year=2008 |volume=28 |pages=41–52 |title=Eocene actinopterygian fishes from Pakistan, with the description of a new genus and species of channid (channiformes) |journal=Journal of Vertebrate Paleontology |last1=Murray |first1=A. M. |last2=Thewissen |first2=J. G. M. |s2cid=85925173 }}</ref><ref>{{cite journal |last1=Roe |first1=L. J. |year=1991 |hdl=2027.42/48541 |title=Phylogenetic and Ecological Significance of Channidae (Osteichthyes Teleostei) from the Early Eocene Kuldana Formation of Kohat, Pakistan |journal = Contributions from the Museum of Paleontology |volume=28 |issue=5 |pages=93–100 }}</ref> By 17 Mya, during the Early Miocene, Channidae had spread into western and central Eurasia, and by 8 Mya, during the late Tortonian, they existed throughout Africa and East Asia.<ref name="Böhme">{{cite journal |doi=10.1130/G20316.1 |title=Migration history of air-breathing fishes reveals Neogene atmospheric circulation patterns |journal=Geology |volume=32 |issue=5 |pages=393 |year=2004 |last1=Böhme |first1=M. |bibcode=2004Geo....32..393B }}</ref> As the 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 the Intertropical Convergence Zone, which increased air humidity, and the intensification of the East Asian monsoon. Both weather patterns emerged due to greater vertical growth of the Alps, Pyrenees, and Himalayas, which affected Eurasian climatic patterns.<ref name="Böhme"/>

==Ecological concerns== [[File:Gabus 070909 0242 rwg.jpg|thumb|right|Snakehead murrel, ''Channa striata'', Java, Indonesia]] Snakeheads can become invasive species and cause ecological damage because, in many areas to which they are not native, the absence of natural enemies makes them an apex predator. Not only can they breathe air, but they can also survive on land for up to four days, provided they are wet, and are known to migrate up to 400 m (1/4 mi) on wet land to other bodies of water by wriggling with their bodies and fins. ''National Geographic'' has referred to snakeheads as "fishzilla"<ref name="natgeo-1">{{cite web|url=http://ngcblog.nationalgeographic.com/ngcblog/2007/12/snakehead_frenzy.html |archive-url=https://web.archive.org/web/20071208013918/http://ngcblog.nationalgeographic.com/ngcblog/2007/12/snakehead_frenzy.html |url-status=dead |archive-date=December 8, 2007 |title=Snakehead Frenzy! |work=NGC Blog |publisher=National Geographic Channel |date=2007-12-03 |first=Elena |last=Cruz}}</ref> and the National Geographic Channel reported the "northern snakehead reaches sexual maturity by age two or three. Each spawning-age female can release up to 15,000 eggs at once. Snakeheads can mate as often as five times a year. This means in just two years, a single female can release up to 150,000 eggs."<ref name="natgeo-2">{{cite web|url=http://channel.nationalgeographic.com/series/wild/3449/Overview#tab-Videos/03181_10 |title=Fishzilla: Snakehead Invasion |work=Wild |publisher=National Geographic Channel |url-status=dead |archive-url=https://web.archive.org/web/20080515220447/http://channel.nationalgeographic.com/series/wild/3449/Overview |archive-date=2008-05-15 }} Video clip titled: "The Northern Snakehead fish wreaks havoc".</ref>

"Since 2002, it has been illegal to possess a live snakehead in many U.S. states, where they are considered a destructive invasive species."<ref name=usgs2004 /> Virginia has criminalized the "introduction" of snakeheads into the state without specific authorization, although the relevant statute does not explain whether mere importation is sufficient to constitute "introduction into the Commonwealth" or whether instead release into the environment is required.<ref>[http://law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-313.2/ Code of Virginia § 18.2-313.2]: "Any person who knowingly introduces into the Commonwealth any snakehead fish of the family Channidae[...] without a permit from the Director of Game and Inland Fisheries [...] is guilty of a class 1 misdemeanor [punishable by up to 12 months in jail and/or a fine of up to $2,500]."</ref>

===Intentional introductions=== Humans have been introducing snakeheads to nonindigenous waters for over 100 years. In parts of Asia and Africa, the snakehead is considered a valuable food fish, since the flesh is very tender and is produced in aquacultures (fisheries motivation) or by accidental release (as was the case in Crofton, Maryland).<ref>{{cite magazine |last=Fields |first=Helen |date=February 2005 |title=Invasion of the Snakeheads |at=Science |magazine=Smithsonian |url=https://www.smithsonianmag.com/science-nature/invasion-of-the-snakeheads-85051261/ }}</ref> Examples of the introduction of snakeheads to nonindigenous waters include: * ''Channa maculata'' was introduced to Madagascar and to Hawaii around the end of the 19th century. It can still be found there today. * ''Channa striata'' was introduced to islands east of the Wallace line by governmental programs in the latter half of the 20th century. In Fiji, the introduction failed. * ''Channa asiatica'', which is native to southern China, was introduced to Taiwan and southern Japan; the origin of and reason for the introduction are unknown. * ''Channa argus'', which is native to northern China's Amur River, was introduced to central Asia (Kazakhstan, Turkmenistan, and Uzbekistan). It was introduced from the Korean Peninsula to Japan about 100 years ago due to fisheries' motivations. Its introduction to Czechoslovakia by its government in the 1960s failed.

===Reported sightings=== ====In the United States====  Snakeheads became a national news topic in the United States because of the appearance of ''C. argus'', commonly known as northern snakeheads, spawning in a Crofton, Maryland, pond in 2002.<ref name="usgs2004">Courtenay, Jr., Walter R. and James D. Williams. [https://pubs.er.usgs.gov/publication/cir1251 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. Retrieved 2021-07-05.</ref> Northern snakeheads became permanently established in the Potomac River around 2004,<ref name="baltsun">[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.</ref> and possibly established in Florida.<ref name="usgs2004" /> In about {{convert|120|mi|abbr=on}} of river, the population has surpassed 21,000 individuals.<ref>{{Cite web|url=http://news.nationalgeographic.com/2016/03/160317-snakeheads-potomac-river-chesapeake-bay-invasive-species-fish/|archive-url=https://web.archive.org/web/20160319141417/http://news.nationalgeographic.com/2016/03/160317-snakeheads-potomac-river-chesapeake-bay-invasive-species-fish/|url-status=dead|archive-date=March 19, 2016|title=Fishermen Battle Invasive 'Frankenfish' Snakeheads|first=Brian |last=Clark Howard |website=National Geographic News|access-date=2016-03-18|date=2016-03-17}}</ref>

According to the United States Environmental Protection Agency, snakeheads have also been spotted in California, Delaware, Florida, Georgia, Hawaii, Maine, Maryland, Massachusetts, Virginia, Louisiana,<ref>{{cite web | url=https://www.nola.com/news/environment/snakehead-aggressive-air-breathing-fish-invades-louisiana/article_51a2c736-06e0-11ee-b4a0-037e655cd1dc.html | title=The snakehead is here: Aggressive, air-breathing fish makes first appearance in Louisiana | date=9 June 2023 }}</ref> and Rhode Island.<ref name="EPA">"History of introduction in the United States: Four species of snakeheads (''Channa argus, C. marulius, C. micropeltes,'' and'' C. striata'') have been recorded from open waters of the United States (California, Florida, Hawaii, Maine, Maryland, Massachusetts, and Rhode Island), and two have become established as reproducing populations." [https://web.archive.org/web/20030819022205/http://www.epa.gov/EPA-IMPACT/2002/October/Day-04/i25337.htm Injurious Wildlife Species; Snakeheads] Environmental Protection Agency. Retrieved 17 February 2008.</ref> Snakeheads have also been spotted in New York State according to the state's Department of Environmental Conservation.<ref>{{cite web |title=Invasive Northern Snakehead - NYS Dept. of Environmental Conservation |url=https://www.dec.ny.gov/animals/45470.html |website=NYS DEC |publisher=New York State |access-date=18 November 2020}}</ref> Snakeheads have been caught in New Jersey since at least 2008, and according to the New Jersey Department of Environmental Protection, the snakehead population appears to be growing and expanding its distribution. Due to the extensive habitat available and sheer size of the Delaware River, complete eradication of the species does not appear to be feasible.<ref>{{Cite web |title="Snakehead Management Activities: 2010" |url=https://www.state.nj.us/dep/fgw/pdf/fwfisheries/invasive_snakehead10.pdf}}</ref>

==== World record ==== According to the International Game Fish Association, two {{cvt|13.61|kg|lboz}} giant snakeheads, both from Rawang, Malaysia, are tied for the record.<ref>{{cite web |url=https://igfa.org/member-services/world-record/common-name/Snakehead,%20giant|title=Snakehead, giant (''Channa micropeltes'')|website=International Game Fish Association|access-date=18 August 2024}}</ref>

==Culinary use== Snakeheads are valuable food fish. Called ''nga yant'' in Burmese and in Manipur [Meiteilon] ''porom'', they are prized fish eaten in a variety of ways. In the southern Indian state of Kerala, it is used to make Varal curry, named after the Malayalam name of the state, Varal (Malayalam: വരാൽ). In Vietnam, they are called ''cá lóc'', ''cá quả'', or ''cá chuối'', and are served in clay-pot, steamed, and pickled preparations. Larger species, such as ''C. striata'', ''C. maculata'', and ''Parachanna obscura'', are farmed in aquaculture. In the United States, chefs have suggested controlling the snakehead invasion by serving them in restaurants.<ref>{{cite web |url=http://news.msn.com/pop-culture/chefs-solution-for-invading-frankenfish-eat-em |title=Chefs' solution for invading 'Frankenfish'? Eat 'em |publisher=News.msn.com |access-date=2014-03-20 |archive-url=https://web.archive.org/web/20140320040239/http://news.msn.com/pop-culture/chefs-solution-for-invading-frankenfish-eat-em |archive-date=2014-03-20 |url-status=dead }}</ref> In Indonesia, snakehead fish, called ''ikan gabus'', are served as the main parts of traditional dishes such as the Betawi people's ''pucung gabus'', and considered to be a delicacy due to their rarity in the wild and in aquaculture, as they are harder to raise than other popular freshwater fish such as catfish and carp. In the Philippines, where it is called ''haluan'' (the Tagalogs call it ''dalag''), it is a favorite among Maguindanaons and Iranuns.

thumb|right|''C. pleurophthalma''

==Classification== The snakeheads comprise two extant genera: * ''Channa'' Scopoli, 1777 (49 species native to Asia) * ''Parachanna'' Teugels & Daget 1984 (three extant species, one fossil species, all native to Africa)

Two other genera are only known from fossils: * †''Anchichanna'' Murray & Thewissen, 2008<ref name = Murray>{{cite journal | author1 = A. M. Murray | author2 = J.G.M. Thewissen | name-list-style = amp | title = Eocene actinopterygian fishes from Pakistan, with the description of a new genus and species of channid (channiformes) | doi = 10.1671/0272-4634(2008)28[41:EAFFPW]2.0.CO;2 | journal = Journal of Vertebrate Paleontology | year = 2008 | volume = 28 | issue = 1 | pages = 41–52| s2cid = 85925173 }}</ref> (one species) * †''Eochanna'' Roe, 1991 (one species) The genus ''Aenigmachanna'' was initially classified in the Channidae upon its discovery, but analysis supports it being reclassified into its own family, Aenigmachannidae.<ref>{{Cite journal|last1=Britz|first1=Ralf|last2=Dahanukar|first2=Neelesh|last3=Anoop|first3=V. K.|last4=Philip|first4=Siby|last5=Clark|first5=Brett|last6=Raghavan|first6=Rajeev|last7=Rüber|first7=Lukas|date=2020-09-30|title=Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India|journal=Scientific Reports|language=en|volume=10|issue=1|pages=16081|doi=10.1038/s41598-020-73129-6|pmid=32999397|pmc=7527459|bibcode=2020NatSR..1016081B |issn=2045-2322|doi-access=free}}</ref>

==In popular culture==  After its release in non-native North American waters, either accidentally or intentionally, the aggressive and predator-free snakehead's reputation as a "Frankenfish"<ref name="bc">{{cite web|url=https://www.cbc.ca/news/canada/british-columbia/b-c-s-snakehead-caught-after-burnaby-pond-drained-1.1242793 |title=B.C.'s snakehead caught after Burnaby pond drained. CBC News (Posted: June 8, 2012) |publisher=Cbc.ca |date=2012-06-08 |access-date=2014-03-20}}</ref> or "monster fish" has become part of popular culture.<ref>"The Ultimate Monster Fish: The Frankenfish Snakehead", Carina Suarez, 28 July 2014, [https://web.archive.org/web/20140913193821/http://tvblogs.nationalgeographic.com/2014/07/28/the-ultimate-monster-fish-the-frankenfish-snakehead/ National Geographic]</ref> Snakeheads have been mentioned on TV shows such as ''The Sopranos<ref>"Soprano Home Movies" episode 13, season six, ''The Sopranos'', 8 April 2007, HBO</ref> and The Office''.<ref>{{Citation|title=Blackmail - The Office US|date=2018-02-24|url=https://www.youtube.com/watch?v=OKRo6SAwYKA|access-date=2018-04-01}}{{cbignore}}{{Dead YouTube link|date=February 2022}}</ref>

[[File:Amia calva 4.jpg|thumb|right|A bowfin, a living fossil, often confused with the snakehead]]

==See also== * Amphibious fish * Bowfin

==References== {{Reflist}}

==Further reading== * {{FishBase family | family = Channidae | month = January | year = 2006}} * {{ITIS | taxon = Channidae | id = 166661 | access-date = 20 March 2006}}

==External links== {{Commons category|Channidae}} {{Wikispecies|Channidae}} * [https://pubs.er.usgs.gov/publication/cir1251 Snakeheads—A Biological Synopsis and Risk Assessment] published by the U.S. Geological Survey * [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 * [https://web.archive.org/web/20051212212509/http://www.scinet.cc/articles/northern-snakehead/frankenfish.html Overview of Northern Snakehead biology] * [https://web.archive.org/web/20060822125124/http://www.mauricemartin.net/snakehead.htm Fish or Foul: Snakeheads near Washington, D.C., and the people who love them] * [https://www.middletownpress.com/middletown/article/Connecticut-s-only-snakehead-predator-fish-17279610.php Sighting of snakehead predator fish in CT has DEEP 'concerned']

Category:Channidae Category:Freshwater fish of China Category:Fish of Indonesia Category:Freshwater fish of Taiwan Category:Fish of Central Asia Category:Extant Eocene first appearances Category:Taxa named by Henry Weed Fowler