Revision 168089 of "ត្រីរាជ" on kmwiki

{{confused|giant pangasius}}
{{Taxobox
| name = ត្រីរាជ
| image = AquatottoGifu mekonoonamazu.jpg
| status = CR
| status_system = iucn3.1
| status_ref = <ref name=IUCN>{{IUCN| id = 15944| taxon = ''Pangasianodon gigas''| assessors = Hogan, Z.| assessment_year = 2011| version = 2011.2| accessdate = 16 April 2012}}</ref>
| trend = down
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Actinopterygii]]
| ordo = [[Siluriformes]]
| familia = [[Pangasiidae]]
| genus = '''''[[Pangasianodon]]'''''
| species = '''''P. gigas'''''
| binomial = ''Pangasianodon gigas''
| binomial_authority = [[Pierre Chevey|Chevey]], 1931
| synonyms = 
''Pangasius paucidens''<br /><small>Fang & Chaux, 1949</small>
}}
<!-- Image with unknown copyright status removed: [[Image:mekongfish.jpg|thumb|{{deletable image-caption|1=Wednesday, 3 September 2008}}]] -->

The '''Mekong giant catfish''', ''Pangasianodon gigas'', ({{lang-th|ปลาบึก}} /ˈplaa bʉ̀k/; {{lang-lo|ປາບຶກ}} /pàː bɨ̆k/; {{lang-km|ត្រីរាជ}} /trəy riec/; {{lang-vi|Cá tra dầu}}) is a [[species]] of [[catfish]] ([[order (biology)|order]] Siluriformes) in the [[shark catfish]] [[family (biology)|family]] (family Pangasiidae), native to the [[Mekong]] basin in [[Southeast Asia]].

In [[Thai folklore]], this fish is regarded with reverence, and special rituals are followed and offerings are made before fishing it.<ref>[http://www.chiangmai-chiangrai.com/pla_buek-giant_catfish.html Pla Buek: The Giant Catfish of the Mae Khong River Chiangrai]</ref>

==Species characteristics==
The Mekong giant catfish is perhaps the most interesting and most threatened species in the Mekong River.  For this reason, conservationists have chosen it as a sort of “flagship” species to promote conservation on the Mekong.<ref>{{cite doi|10.1023/B:EBFI.0000033487.97350.4c}}</ref><ref>MGCCG, 2005</ref> With recorded sizes of up to 10.5 ft (3.2 m) and 660 lb (300 kg), the Mekong’s giant catfish currently holds the ''[[Guinness Book of World Records]]''' position for the world’s largest freshwater fish.<ref>(Mydans et al. 2005, Hogan et al. 2004, Hogan et al. 2007)</ref> Although research projects are currently ongoing, relatively little is known about this species.  Historically, the fish's natural range reached from the lower Mekong in Vietnam (above the tidally influenced brackish water of the river’s delta) all the way to the northern reaches of the river in the Yunnan province of China, spanning almost the entire 4,800-km length of the river.<ref>(Lopez et al. 2007, Hogan et al. 2007)</ref> Due to threats, this species no longer inhabits the majority of its original [[habitat]]; it is now believed to only exist in small, isolated populations in the middle Mekong region.<ref name="Hoganet">(Hogan et al. 2004)</ref> Fish congregate during the beginning of the rainy season and migrate upstream to spawn.<ref name="Hoganet" /> They live primarily in the main channel of the river, where the water depth is over 10 m,<ref>(Mattson et al. 2002)</ref> while researchers, fishermen and officials have found this species in the [[Tonle Sap]] River and Lake in Cambodia, a UNESCO Biosphere reserve.  In the past, fishermen have reported the fish in a number of the Mekong’s tributaries; today, however, essentially no sightings are reported outside of the main Mekong river channel and the Tonle Sap region.

In infancy, this species feeds on zooplankton in the river and is known to be cannibalistic.<ref name="Pholprasith">(Pholprasith, 1983 as cited in Mattson et al. 2002)</ref> After approximately one year, the fish becomes herbivorous, feeding on filamentous algae, probably ingesting larvae and periphyton accidentally.<ref> (Pookaswan, 1989 and Jensen, 1997 as cited in Mattson et al. 2002)</ref>  The fish likely obtains its food from algae growing on submerged rocky surfaces, as it does not have any sort of dentition.<ref name="Pholprasith" />

==Conservation==
Endemic to the lower half of the Mekong river, this catfish is in danger of extinction due to overfishing, as well  as the decrease in water quality due to development and upstream damming by the [[People's Republic of China]]. The current [[IUCN Red List]] for fishes classes the species as Critically Endangered; the number living in the wild is unknown, but catch data indicate the population has fallen by 80% in the last 14 years.<ref name=IUCN/><ref name="ng_20031118">{{cite news
|url=http://news.nationalgeographic.com/news/2003/11/1118_031118_giantcatfish.html
|title=Giant Catfish Critically Endangered, Group Says
|publisher=[[National Geographic (magazine)|National Geographic]] News
|date=2003-11-18
|accessdate=2006-06-29
}}</ref>
It is also listed in Appendix I of [[CITES]], banning international trade.<ref name="cites">{{cite web
|url=http://www.cites.org/eng/app/appendices.shtml
|title=CITES Appendices I, II and III
|publisher=[[CITES]]
|date=2006-06-14
|accessdate=2006-06-29
}}</ref>

In ''The Anthropologists' Cookbook'' (1977), Jessica Kuper noted the importance of the ''pa beuk'' to the Lao people and remarked, "In times gone by, this huge fish, which is found only in the Mekong, was fairly plentiful; but in the last few years the number taken annually has dwindled to forty, thirty or twenty, and perhaps in 1976 even fewer. This is sad, as it is a noble fish and a mysterious one, revered by the Lao."<ref>{{cite book |title=The Anthropologists' Cookbook |last=Kuper  |first=Jessica  |year=1977 |publisher=Universe Books |location= |isbn= |page=167 |pages= |url= |accessdate=}}</ref>

Fishing for the Mekong giant catfish is illegal in the wild in [[Thailand]], [[Laos]], and [[Cambodia]], but the bans appear to be ineffective, with the fish continuing to be caught in all three countries.<ref name=IUCN/> However, in recognition of the threat to the species, nearly 60 Thai fishermen agreed to stop catching the endangered catfish in June 2006, to mark the 60th anniversary of [[Bhumibol Adulyadej|Bhumibol Adulyadej's]] ascension to the throne of Thailand.<ref name="bbc">{{cite news
|url=http://news.bbc.co.uk/2/hi/asia-pacific/5068206.stm
|title=Giant Mekong catfish off the hook
|date=2006-06-10
|accessdate=2006-06-29
|publisher=BBC News
}}</ref> Thailand is the only country to allow fishing for private stocks of Mekong giant catfish. This helps save the species, as lakes purchase the small fry from the government breeding program, generating extra income that allows the breeding program to function. Fishing lakes, such as Bung Sam Ran in Bangkok, have the species up to 140&nbsp;kg;. The most common size landed is 18&nbsp;kg, although some companies specialise in landing the larger fish.

The species needs to reach 50 to 70&nbsp;kg to breed, and unfortunately it does not breed in lakes. The Thailand Fishery Department has instituted a breeding program to restock the Mekong River. However, it is yet to be seen if the fish will spawn.

==Size==
Attaining an unconfirmed length of {{convert|3|m|abbr=on}}, the Mekong giant catfish grows extremely quickly, reaching a mass of 150 to 200 [[kilogram|kg]] in only six years.<ref name="fishbase">{{FishBase_species
|genus=Pangasianodon
|species=gigas
|year=2006
|month=March
}}</ref>
The largest catch recorded in Thailand since record-keeping began in 1981 was a female measuring {{convert|2.7|m|abbr=on}} in length and weighing 293&nbsp;[[kilogram|kg]] (646&nbsp;[[pound (mass)|lb]]). This specimen, caught in 2005, is widely recognized as the largest freshwater fish ever caught (although [[sturgeon]] can far exceed this size, they can be [[anadromous]]). Thai Fisheries officials stripped the fish of its eggs as part of a breeding programme, intending then to release it, but the fish died in captivity and was sold as food to local villagers.<ref name="ng_20050629">{{cite news
|url=http://news.nationalgeographic.com/news/2005/06/0629_050629_giantcatfish.html
|title=Grizzly Bear-Size Catfish Caught in Thailand
|publisher=[[National Geographic (magazine)|National Geographic]] News
|date=2005-06-29
|accessdate=2006-06-29
}}</ref><ref name="msnbc">{{cite news
|url=http://msnbc.msn.com/id/8404622/
|title=Fish whopper: 646 pounds a freshwater record
|date=2005-07-01
|accessdate=2006-06-29
}}</ref><ref name="iht">{{cite news
|url=http://www.iht.com/bin/print_ipub.php?file=/articles/2005/08/24/news/fish.php
|title=Hunt for the big fish becomes a race
|author=Mydans, Seth
|publisher=International Herald Tribune
|date=2005-08-25
|accessdate=2006-06-29
|archiveurl=http://web.archive.org/web/20090501184151/http://www.iht.com/bin/print_ipub.php?file=/articles/2005/08/24/news/fish.php|archivedate=2009-05-01}}</ref>

Grey to white in colour and lacking stripes, the Mekong giant catfish is distinguished by the near-total lack of [[barbel (anatomy)|barbel]]s and the absence of teeth.<ref name="fishbase" />

==References==<!-- ZOOLOGICAL SCIENCE 23: 235–238 (2006) -->
{{reflist}}

==External links==
*[http://www.thaifishingguide.com/gallery/freshwater/mekongcatfish/mekong_catfish.html Photographs of sport fishers with their catch]
*[http://news.nationalgeographic.com/news/2007/07/photogalleries/giant-fishes/photo2.html Photo in National Geographic of a large specimen]
*[http://teakdoor.com/view.php?pg=thai_fresh_water_fish Fresh Water Fish of Thailand]
{{DEFAULTSORT:Mekong Giant Catfish}}

[[Category:Pangasiidae]]
[[Category:Megafauna of Eurasia]]
[[Category:Monotypic fish genera]]
[[Category:Animals described in 1931]]
[[Category:Fish of the Mekong Basin]]
[[Category:Fish of Cambodia]]
[[Category:Fish of Laos]]
[[Category:Fish of Thailand]]
[[Category:Fish of Vietnam]]