Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Monopterus albus
(Asian swamp eel)

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Datasheet

Monopterus albus (Asian swamp eel)

Summary

  • Last modified
  • 22 November 2019
  • Datasheet Type(s)
  • Invasive Species
  • Host Animal
  • Preferred Scientific Name
  • Monopterus albus
  • Preferred Common Name
  • Asian swamp eel
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Chordata
  •       Subphylum: Vertebrata
  •         Class: Actinopterygii
  • Summary of Invasiveness
  • The native range of the Asian swamp eel, M. albus, includes tropical, subtropical and temperate climates, rather like the southeastern USA. As this species has the potential to occupy natural aquatic and wetland habitats it is well suit...

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Pictures

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PictureTitleCaptionCopyright
Monopterus albus (Asian swamp eel); adult, head. Florida, USA.
TitleAdult
CaptionMonopterus albus (Asian swamp eel); adult, head. Florida, USA.
Copyright©Paul Shafland/Florida Fish and Wildlife Conservation/Bugwood.org - CC BY-NC 3.0 US
Monopterus albus (Asian swamp eel); adult, head. Florida, USA.
AdultMonopterus albus (Asian swamp eel); adult, head. Florida, USA.©Paul Shafland/Florida Fish and Wildlife Conservation/Bugwood.org - CC BY-NC 3.0 US
Monopterus albus (Asian swamp eel); adults. These live Asian swamp eels were imported from southeast Asia and sold in an urban food markets in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

USGS scientists found parasitic worms (known as gnathostomes) in Asian swamp eels collected between 2010 and 2012 from ethnic food markets and in Florida waters where the eel species is invasive. If eaten raw or undercooked, these eels could transmit their parasites to people, causing mild to serious disease. Severe cases of the infection can lead to blindness, paralysis or death. Also concerning is that this parasite could be transmitted into native fish and wildlife populations and domestic cats or dogs.
TitleAdults
CaptionMonopterus albus (Asian swamp eel); adults. These live Asian swamp eels were imported from southeast Asia and sold in an urban food markets in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters. USGS scientists found parasitic worms (known as gnathostomes) in Asian swamp eels collected between 2010 and 2012 from ethnic food markets and in Florida waters where the eel species is invasive. If eaten raw or undercooked, these eels could transmit their parasites to people, causing mild to serious disease. Severe cases of the infection can lead to blindness, paralysis or death. Also concerning is that this parasite could be transmitted into native fish and wildlife populations and domestic cats or dogs.
CopyrightPublic Domain/released by the US Geological Survey/original photo by Leo Nico
Monopterus albus (Asian swamp eel); adults. These live Asian swamp eels were imported from southeast Asia and sold in an urban food markets in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

USGS scientists found parasitic worms (known as gnathostomes) in Asian swamp eels collected between 2010 and 2012 from ethnic food markets and in Florida waters where the eel species is invasive. If eaten raw or undercooked, these eels could transmit their parasites to people, causing mild to serious disease. Severe cases of the infection can lead to blindness, paralysis or death. Also concerning is that this parasite could be transmitted into native fish and wildlife populations and domestic cats or dogs.
AdultsMonopterus albus (Asian swamp eel); adults. These live Asian swamp eels were imported from southeast Asia and sold in an urban food markets in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters. USGS scientists found parasitic worms (known as gnathostomes) in Asian swamp eels collected between 2010 and 2012 from ethnic food markets and in Florida waters where the eel species is invasive. If eaten raw or undercooked, these eels could transmit their parasites to people, causing mild to serious disease. Severe cases of the infection can lead to blindness, paralysis or death. Also concerning is that this parasite could be transmitted into native fish and wildlife populations and domestic cats or dogs.Public Domain/released by the US Geological Survey/original photo by Leo Nico

Identity

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Preferred Scientific Name

  • Monopterus albus Zuiew, 1793

Preferred Common Name

  • Asian swamp eel

Other Scientific Names

  • Apterigia immaculata Basilewsky, 1855
  • Apterigia nigromaculata Basilewsky, 1855
  • Apterigia saccogularis Basilewsky, 1855
  • Fluta alba Zuiew, 1793
  • Gymnotus albus Zuiew, 1789
  • Monopterus helvolus Richardson, 1846
  • Monopterus javanensis Lacepède, 1800
  • Monopterus marmoratus Richardson, 1846
  • Muraena alba Zuiew, 1793
  • Ophicardia phayriana McClelland, 1844
  • Pneumabranchus cinereus McClelland, 1844
  • Symbranchus grammicus Cantor, 1842
  • Synbranchus xanthognathus Richardson, 1845
  • Unibranchapertura laevis Lacepède, 1803

International Common Names

  • English: mud eel; rice (paddy) field eel; rice eel; rice paddy eel; rice swampeel; risal; swamp eel

Local Common Names

  • Cambodia: antong
  • China/Hong Kong: wong sin
  • Germany: Ostasiatischer Kiemenschlitzaal
  • Indonesia: belut; welut
  • Japan: ta-unagi
  • Laos: ian; l'en; pa lai
  • Malaysia: belut
  • Russian Federation: belobryukhiy ugor'
  • Thailand: lai; pla lai
  • Vietnam: conlu'o'n; luon

Summary of Invasiveness

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The native range of the Asian swamp eel, M. albus, includes tropical, subtropical and temperate climates, rather like the southeastern USA. As this species has the potential to occupy natural aquatic and wetland habitats it is well suited for a variety of habitats in Florida, USA. Its voracious appetite for all aquatic life and ability to survive in extreme conditions indicates it is a potential threat to native wildlife. It has no known natural predators in the USA. Although it prefers tropical waters, it has been known to survive in sub-zero temperatures. It can tolerate salinities of up to 16 ppt (Schofield and Nico, 2003) and breathe air, thereby surviving out of water or in moist soils for extended periods. In some populations, young hatch as females, mature as females then transform into larger males. The males guard eggs aggressively, increasing reproductive success. Not only do they seem to be able to feed voraciously, with no limit to their appetite, they have also been known to survive months without food or water.

Although there are no references to problems with introduction or of existing populations in Hawaii, the species is considered a high priority for control in Georgia and Florida, USA.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Chordata
  •             Subphylum: Vertebrata
  •                 Class: Actinopterygii
  •                     Order: Synbranchiformes
  •                         Family: Synbranchidae
  •                             Genus: Monopterus
  •                                 Species: Monopterus albus

Description

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Cylindrical body with no scales, pectoral or pelvic fins. Dorsal, caudal and anal fins reduced to folds of skin without fin rays. No rostral appendage. Gill openings fused into a single aperture, located under the head. Swimbladder and ribs absent. Blunt, round snout; upper lip thick, overlapping part of lower lip. Teeth on jaws and palate. Eyes small, covered by a layer of skin (Nichols, 1943; Jayaram, 1981). Red to brown coloration with small dark spots across back and occasionally on the ventral surface (Inger and Kong, 1962). Lateral line well developed (Jayaram, 1981). Able to change sex during life cycle. Maximum length of 1 m and weight of 0.45 kg.

Distribution

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The rice eel is native to eastern and southern Asia, and also possibly indigenous to Australia. It can be found in muddy ponds, canals, medium to large rivers, rice fields and swamps. First introduced to the USA, in Hawaii around 1900 for the food fishery sector. In 1994, reported in northeastern Georgia and in 1997 in southern Florida; these are likely to have been the result of fish farm escape or release or aquarium release. Its ability to breed in captivity and survive under oxygen-depleted conditions make it a suitable candidate for aquaculture.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 10 Jan 2020
Continent/Country/Region Distribution Last Reported Origin First Reported Invasive Reference Notes

Asia

CambodiaPresentNative
ChinaPresentNative
-SichuanPresent
Hong KongPresentNative
IndiaPresentNative
IndonesiaPresentNative
JapanPresentPresent based on regional distribution.
-HokkaidoPresentNative
-HonshuPresentNative
LaosPresentNative
MalaysiaPresentNative
MyanmarPresentNative
PhilippinesPresentNative
South KoreaPresentNative
TaiwanPresentNative
ThailandPresentNative
VietnamPresentNative

North America

United StatesPresentIntroducedInvasive
-FloridaPresentIntroducedInvasive
-GeorgiaPresentIntroducedEstablished
-HawaiiPresentIntroducedInvasive
-New JerseyPresentIntroducedSilver Lake, Gibbsboro

Oceania

AustraliaPresentNative

Introductions

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Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Florida 1997 Unknown Yes Nico (2004)
Georgia 1994 Unknown Yes Nico (2004)
Hawaii Asia 1900 Aquaculture (pathway cause)Unknown Yes Welcomme (1988)

Habitat List

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CategorySub-CategoryHabitatPresenceStatus
Freshwater
Brackish

Biology and Ecology

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See Fuller et al. (2011) for details on the ecology of this species.

Climate

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ClimateStatusDescriptionRemark
A - Tropical/Megathermal climate Preferred Average temp. of coolest month > 18°C, > 1500mm precipitation annually

Pathway Causes

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CauseNotesLong DistanceLocalReferences
FoodPresumed to have been brought to Hawaii by Asian immigrants as a food fish Yes Fuller et al., 2011
Intentional releasePresence in Florida and Georgia most likely due to aquarium release (or fish farm escape in Florida) Yes Fuller et al., 2011

Impact Summary

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CategoryImpact
Biodiversity (generally) Negative
Environment (generally) Negative
Native fauna Negative

Environmental Impact

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When burrowing nests to wait out the dry periods, they may play a part in altering the habitat under ponds and swampy areas. The burrows they dig may become large and branched reaching up to 1.5 m in depth. Hence swamp eels may accelerate the drying of ponds where they are abundant (Aguirre and Poss, 1999).

Impact on Biodiversity

The impact of this species is largely unknown; however, Fuller et al. (2011) note that it may be a potential threat to native fish, frogs and aquatic invertebrates.

Impact: Biodiversity

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Although it is too early to tell, there are fears that the eel may enter the Florida Everglades, USA and influence the native species there. The eels have been spotted within a kilometre of the Everglades National Park (Bricking, 2002).

Uses List

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Human food and beverage

  • Cured meat
  • Fresh meat
  • Live product for human consumption
  • Whole

Prevention and Control

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Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

See Fuller et al. (2011) for further details on the potential use of rotenone and electrofishing to control this species.

References

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Aguirre W; Poss S, 1999. Monopterus albus (Zuiew, 1793). Non-indigenous aquatic species resource. Online. http://nis.gsmfc.org/nis_factsheet.php?toc_id=193. Accessed 18/10/2004.

Bricking EM, 2002. Asian swamp eel (Monopterus albus). Introduced species summary project, Columbia University, USA. Online. http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Monopterus_albus.html. Accessed 18/10/2004.

Fishbase, 2004. Entry for Monopterus albus. Main ref. Talwar PK, Jhingran AG, 1991. Inland fishes of India and adjacent countries. Volume 2. Rotterdam: AA Balkema, 778-779. Online at www.fishbase.org. Accessed 25/02/2004.

Froese R; Pauly D, 2010. FishBase. http://www.fishbase.org

Fuller PL; Nico LG; Cannister M, 2011. Monopterus albus. USGS Nonindigenous Aquatic Species Database. Gainesville, Florida, USA: USGS. http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=974

Garde SV; Sheth AR, 1992. Induced ovulation of rice-field eel (Monopterus albus) by a synthetic nonapeptide. Indian Journal of Experimental Biology, 30(11):1111-1113.

Guan RZ; Zhou LH; Cui GH; Feng XH, 1996. Studies on the artificial propagation of Monopterus albus (Zuiew). Aquaculture Research, 27(8):587-596.

Inger RF; Kong CP, 1962. The fresh-water fishes of north Borneo. Fieldiana: Zoology, 45:1-268.

Jayaram KC, 1981. The freshwater fishes of India, Pakistan, Bangladesh, Burma and Sri Lanka – A handbook. Calcutta: Zoological Survey of India, 475 pp.

Liem KF, 1987. Functional design of the air ventilation apparatus and overland excursions by teleosts. Fieldiana: Zoology 37:1-29.

Nichols JT, 1943. The freshwater fishes of China. Natural history of Central Asia: Volume IX. New York, USA: The American Museum of Natural History, 322 pp.

Nico L, 2004. Monopterus albus. Non-indigenous Aquatic Species Database, Gainesville, Florida, USA. Online. http://nas.er.usgs.gov/queries/SpFactSheet.asp?SpeciesID=974. Accessed 18/10/2004.

Rainboth WJ, 1996. FAO species identification field guide for fishery purposes. Fishes of the Cambodian Mekong. FAO species identification field guide for fishery purposes. Fishes of the Cambodian Mekong., xi + 265 pp..

Schofield PJ; Nico LG, 2003. Salinity tolerance of introduced swamp eels: Implications for range expansion in south Florida. Poster presented at the Joint Conference on the Science and Restoration of the Greater Everglades and Florida Bay Ecosystem, Palm Harbor, FL, April 2003.

Shu MA; Ma YZ; Zhang JC, 2000. An analysis of the nutritive composition in muscle of Monopterus albus. Journal of Fisheries of China, 24:339-344.

Shu MiaoAn; Xu HaiSheng, 2001. An analysis of mineral elements in muscle of mud eel (Monopterus albus). Journal of Shanghai Agricultural College, 19(3):195-197.

Smith HM, 1945. The fresh-water fishes of Siam, or Thailand. Bulletin of the US National Museum (Smithsonian Institution) 188:1-622.

Sterba G, 1973. Freshwater fishes of the world. Neptune City, NJ, USA: Tropical Fish Hobbyist Publications, Inc.

Tao YX; Lin HR; Kraak Gvan der; Peter RE, 1993. Hormonal induction of precocious sex reversal in the ricefield eel, Monopterus albus. Aquaculture, 118(1-2):131-140.

Vishwanath W; Lilabati H; Bijen M, 1998. Biochemical, nutrition and microbiological quality of fresh and smoked mud eel fish Monopterus albus - a comparative study. Food Chemistry, 61(1/2):153-156; 23 ref.

Welcomme RL, 1988. International introductions of inland aquatic species. FAO Fisheries Technical Paper, No. 294:x + 318 pp.

Yang DQ; Chen F; Li DX; Liu BT, 2000. Requirements of nutrients and optimum energy-protein ratio in the diet for Monopterus albus. Journal of Fisheries of China, 24:259-262.

Distribution References

Anon, 2010. FishBase. In: FishBase, [ed. by Froese R, Pauly D]. http://www.fishbase.org

CABI Data Mining, 2001. CAB Abstracts Data Mining.,

CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

Fishbase, 2004. Entry for Monopterus albus. In: Inland fishes of India and adjacent countries, 2 [ed. by Talwar PK, Jhingran AG]. Rotterdam, AA Balkema. 778-779. http://www.fishbase.org

Fuller PL, Nico LG, Cannister M, 2011. Monopterus albus. USGS Nonindigenous Aquatic Species Database., Gainesville, Florida, USA: USGS. http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=974

Links to Websites

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WebsiteURLComment
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gatewayhttps://doi.org/10.5061/dryad.m93f6Data source for updated system data added to species habitat list.
Global register of Introduced and Invasive species (GRIIS)http://griis.org/Data source for updated system data added to species habitat list.

Contributors

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Main Author
Uma Sabapathy Allen
Human Sciences, CAB International, Wallingford, Oxon, OX10 8DE, UK

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