Gambusia affinis
(western mosquitofish)

Pictures

Picture	Title	Caption	Copyright
Title Artwork of adult fish Caption Gambusia affinis (mosquito fish); artwork of adult fish. Copyright ©Duane Raver/US Fish and Wildlife Service/Bugwood.org - CC BY-NC 3.0 US	Artwork of adult fish	Gambusia affinis (mosquito fish); artwork of adult fish.	©Duane Raver/US Fish and Wildlife Service/Bugwood.org - CC BY-NC 3.0 US

Identity

Preferred Scientific Name

• Gambusia affinis Biard and Girard, 1853

Preferred Common Name

• western mosquitofish

Other Scientific Names

• Gambusia affinis affinis Biard and Girard, 1853
• Gambusia affinis katruelis Biard and Girard, 1853
• Gambusia gracilis Girard, 1859
• Gambusia humilis Gunher, 1866
• Gambusia patruelis Biard and Girard, 1853
• Haplochilus melanops Cope, 1870
• Heterandria affini Biard and Girard, 1853
• Heterandria patruelis Biard and Girard, 1853
• Zygonectes brachypterus Cope, 1880
• Zygonectes gracilis Girard, 1859
• Zygonectes inurus Jordan and Gilbert, 1882
• Zygonectes patruelis Biard and Girard, 1853

International Common Names

• English: mosquito fish; mosquitofish

Local Common Names

• Albania: burkaleci
• Canada: gambusie
• China/Hong Kong: live-bearing tooth-carp; sang hang ue; tes; topminnow
• France: alevin; gambouse; gambuse; gambusie
• Germany: Koboldkarpfling; Silberkarpfling; Texaskarpfling
• Greece: kounoupopsaro
• Japan: kadayashi
• Philippines: isdang canal
• Poland: gambuzia pospolita
• Portugal: gambuzia
• Russian Federation: obyknovennaya gambuziya
• Spain: gambusino
• Sweden: vastlig moskitfisk
• Ukraine: gambuzija

Summary of Invasiveness

G. affinis has been introduced throughout the world as a mosquito-control agent. It has become a pest in many waterways following initial introductions in the early 1900s. G. affinis is a highly predatory fish, that as well as controlling mosquitoes also eats the eggs of economically important fish, and preys on rare indigenous fish and invertebrate species (ISSG, 2010).

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Chordata
•             Subphylum: Vertebrata
•                 Class: Actinopterygii
•                     Order: Cyprinodontiformes
•                         Family: Poeciliidae
•                             Genus: Gambusia
•                                 Species: Gambusia affinis

Notes on Taxonomy and Nomenclature

Description

G. affinis is a small, stout, robust, dull grey to brown with a terminal and upward pointing mouth adapted for feeding at the surface of the water. It has a small, rounded dorsal fin that originates behind the anal fin. Dorsal fin rays are 7-9 in number, and anal rays are 9-10 (FishBase, 2004). Origin of seventh dorsal fin is opposite anal ray. There are 8 horizontal scale rows between back and abdomen. The first few rays of the anal fin are greatly elongated in adult males. Mature females are larger than males. The maximum total length reported for male and female is 4.0 cm (Billard, 1997) and 7.0 cm respectively (FishBase, 2004).

Distribution

Native range of G. affinis is recorded as Atlantic and Gulf Slope drainage from southern New Jersey, USA to Mexico; Mississippi River basin from central Indiana and Illinois, USA south to Gulf (USGS, 2003). Because of its reputation as a mosquito-control agent, G. affinis has been stocked routinely and indiscriminately in temperate and tropical areas around the world resulting in a wide distribution. Due to their hardiness, this species may now be the most widespread freshwater fish in the world (USGS, 2003).

For non-indigenous occurrences of G. affinis within the USA please see the USGS fact sheet on this species (Nico et al., 2007).

Because G. affinis and G. holbrooki were treated as subspecies of G. affinis prior to 1988, it is not always possible to discern which species is referred to in the earlier literature and the Distribution and Intrroductions Tables may include records of G. holbrooki. It was confirmed by Pyke (2005) that records across Australia were of G. holbrooki. 

Distribution Table

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.

Introductions

Habitat List

Natural Food Sources

Climate

Water Tolerances

Natural enemies

Means of Movement and Dispersal

Intentional Introduction

Intentional release of G. affinis is carried out by mosquito-control agencies.

Pathway Causes

Impact Summary

Environmental Impact

G. affinis has been regarded as a controversial species as it has created ecological problems of various kinds but is, at the same time, perceived as being extremely useful in controlling unwanted organisms (Welcomme, 1988). According to Courtenay and Meffe (1989), mosquitofish have had the greatest ecological impact by far of any of the introduced poeciliids. Although widely introduced as mosquito control agents, recent critical reviews of the world literature on mosquito control have not supported the view that Gambusia are particularly effective in reducing mosquito populations or in reducing the incidence of mosquito-borne diseases (Courtenay and Meffe, 1989).

Because of the aggressive and predatory behaviour of G. affinis, it is reported that native fish species and populations of small fish tend to decline, or are eliminated in areas where it has become established. In some habitats, introduced G. affinis reportedly displaced select native fish species regarded as better or more efficient mosquito control agents. They have been particularly destructive in the American West where they have contributed to the elimination or decline of populations of federally endangered and threatened species (Courtenay and Meffe, 1989). Mosquitofish, and other introduced poeciliids, have been implicated in the decline of native damselflies on Oahu, Hawaii. Often the distributions of the damselflies and introduced fishes were found to be mutually exclusive, probably resulting from predation of the fish on the insects (Englund, 1999).

For further information on predation see Threat Abatement Plan for Gambusia holbrooki (NSW National Parks and Wildlife Service, 2003).

Threatened Species

Risk and Impact Factors

• Proved invasive outside its native range
• Highly adaptable to different environments
• Has high reproductive potential

• Ecosystem change/ habitat alteration
• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition (unspecified)
• Hybridization
• Predation

• Highly likely to be transported internationally deliberately

Uses List

Animal feed, fodder, forage

• Live feed

Environmental

• Biological control

General

• Ornamental

Similarities to Other Species/Conditions

G. affinis can be confused with G. holbrooki and at one time they were classified as the subspecies G. affinis affinis and G. affinis holbrooki, respectively (Froese and Pauly, 2007).

Prevention and Control

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.

Control

Chemical control

Chemical control of mosquitofish was investigated by Willis and Ling (2000) in New Zealand in fish living alongside the black mudfish, Neochanna diversus. The relative sensitivities of the mudfish and mosquitofish to the chemical compound rotenone were tested to determine whether the piscicide could be used to remove the mosquitofish from the mudfish habitats – the former having detrimental effects of the survival of mudfish. Rotenone was chosen as although it is extremely toxic to fish by acting by blocking cellular oxygen uptake causing fish to gasp at the water’s surface, non-target fish can be saved by removal to freshwater or by the addition of a strong oxidising agent.

Their study found that mudfish were approximately twice as sensitive to rotenone as mosquitofish; however, when mudfish were removed from the treated areas they did fully recover. Willis and Ling concluded that the application of rotenone to wetland standing water could only be used to control mosquitofish numbers rather than eliminate them completely.

References

Allen GR, 1991. Field guide to the freshwater fishes of New Guinea. Madang, Papua New Guinea: Christensen Research Institute, 180 pp.

Ang KJ, Gopinath R, Chua TE, 1989. The status of introduced fish species in Malaysia. In: De Silva SS, ed. Exotic aquatic organisms in Asia. Proceedings of the Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fisheries Society. Special Publication 3. Manila, Philippines: Asian Fisheries Society, 71-82.

Arkhipchuk VV, 1999. Chromosome database. Database of Dr. Victor Arkhipchuk. Ukraine.

Bell-Cross G, Minshull JL, 1988. The fishes of Zimbabwe. National Museums and Monuments of Zimbabwe, Harare. 294 pp.

Billard R, 1997. Les poissons d’eau douce des rivieres de France. Identification, inventaire et repartition des 83 especes. Lausanne: Delachaux and Niestle, 192 pp.

Burgess GH, Franz R, 1989. Zoogeography of the Antillean freshwater fish fauna. In: Woods CA, ed. Biogeography of the West Indies: past, present, and future, 236-304.

Chiba K, Taki Y Sakai K, Oozeki Y, 1989. Present status of aquatic organisms introduced into Japan. In: De Silva SS, ed., Exotic aquatic organisms in Asia, Proceedings of the Workshop on Introduction of Exotic Aquatic Organisms in Asia, p 63-70, Asian Fish Soc. Spec. Publ. 3,. Manila, Philippines: Asian Fish Society.

Coad BW, 1981. Fishes of Afghanistan, an annotated check-list. Publications in Zoology, National Museums of Canada, 14:23.

Courtenay WRJr, Meffe GK, 1989. Small fishes in strange places: a review of introduced poeciliids. Ecology and evolution of livebearing fishes (Poeciliidae)., 319-331.

Eldredge LG, 1994. Perspectives in aquatic exotic species management in the Pacific islands. Volume I. Introduction of commercially significant aquatic organisms to the Pacific islands. South Pacific Commission, Noumea, New Caledonia, 127 pp.

Englund RA, 1999. The impacts of introduced poeciliid fish and Odonata on the endemic Megalagrion (Odonata) damselflies of Oahu Island, Hawaii. Journal of Insect Conservation, 3(3):225-243.

FAO, 1997. FAO Database on Introduced Aquatic Species. FAO, Rome, Italy: Food and Agricultural Organization of the United Nations.

Fishbase, 2004. Entry for Gambusia affinis. Main ref. Page LM, Burr BM, 1991. A field guide to freshwater fishes of North America north of Mexico. Boston: Houghton Mifflin Company, 432 pp. Online at www.fishbase.org. Accessed 17 September 2004.

Froese R, Pauly D, 2007. FishBase. http://www.fishbase.org

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

Gabrielyan BK, 2001. An annotated checklist of freshwater fishes of Armenia. Naga, 24(3/4):23-29.

Gandolfi G, Zerunian S, Torricelli P, Marconato A, eds, 1991. I pesci delle acque interne italiane. Ministero dell’Ambiente e Unione Zoologica Italiana. Instituto Poligrafico e Zecca dello Stato, Roma. 616 pp.

Golani D, Mires D, 2000. Introduction of fishes to the freshwater system of Israel. Isr. J. Aquacult./Bamidgeh, 52(2):47-60.

Gopi KC, 2000. Freshwater fishes of Kerala State. In: Ponniah AG, Gopalakrishnan A, eds. Endemic Fish Diversity of Western Ghats. NBFGR-NATP Publication. Lucknow, UP, India: National Bureau of Fish Genetic Resources, 56-76.

Honebrink R, 1990. Fishing in Hawaii: a student manual. Honolulu, Hawaii: Education Program, Division of Aquatic Resources, 79 pp.

ISSG, 2010. Global Invasive Species Database (GISD). Invasive Species Specialist Group of the IUCN Species Survival Commission. http://www.issg.org/database

Juliano RO, Guerrero R III, Ronquillo I, 1989. The introduction of exotic aquatic species in the Philippines. In: De Silva SS, ed. Proceedings of the Workshop on Introduction of Exotic Aquatic Organisms in Asia: The Asian Fisheries Society, 83-90.

Kamilov G, Urchinov Zh U, 1995. Fish and fisheries in Uzbekistan under the impact of irrigated agriculture. In: Petr T, ed. Inland fisheries under the impact of irrigated agriculture: Central Asia. FAO Fisheries Circular No. 894, 10-41.

Keith P, Allardi J, 1998. The introduced freshwater fish of France: status, impacts and management. In: Cowx IG, ed. Stocking and introduction of fish. Fishing News Books. Bodmin, Cornwall: MPG Books Ltd., 153-166.

Klinkhardt M, Tesche M, Greven H, 1995. Database of fish chromosomes. Westarp Wissenschaften, 179 pp.

Kottelat M, 2001. Fishes of Laos. Colombo, Sri Lanka: WHT Publications Ltd., 198 pp.

Lewis AD, Pring CK, 1986. Freshwater and brackishwater fish and fisheries of Fiji. In: Petr T, ed. Reports and papers presented at the Indo-Pacific Fishery Commission Expert Consultation on inland fisheries of the larger Indo-Pacific islands. Bangkok, Thailand, 4-6 August 1986. FAO Fish. Rep. (371) Suppl., 38-59.

Man SH, Hodgkiss IJ, 1981. Hong Kong freshwater fishes. Hong Kong: Urban Council, Wishing Printing Company, 75 pp.

Masuda H, Amaoka K, Araga C, Uyeno T, Yoshino T, 1984. The fishes of the Japanese Archipelago. Vol. 1. Tokyo, Japan: Tokai University Press, 437 pp.

Mitrofanov VP, Petr T, 1999. Fish and fisheries in the Altai, Northern Tien Shan and Lake Balkhash (Kazakhstan). In: Petr T, ed. Fish and fisheries at higher altitudes: Asia. FAO Fish. Tech. Pap. No. 385. FAO, Rome, 149-167.

Movchan Yu V, 1988. Fauna of Ukraine. Fishes. Loaches, catfishes, channel catfishes, freshwater eels, conger eels, garfishes, codfishes, sticklebacks, seahorses, mosquitofishes, John dories, barracudas, grey mullets, silversides, lings. Kiev: Naukova dumka Publishing House, 8(3), 367 pp.

NBFGR, 1998. Fish chromosome atlas. Lucknow, India: National Bureau of Fish Genetic Resources Special Publication, No. 1, 332 pp.

Nico L, Fuller P, Jacobs G, 2007. Gambusia affinis. USGS Nonindigenous Aquatic Species Database. Gainesville, FL: USGS. http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=845

NSW National Parks Wildlife Service, 2003. NSW Threat Abatement Plan. Predation by Gambusia holbrooki - The Plague Minnow. Hurstville, NSW: NPWS. http://www.nationalparks.nsw.gov.au/PDFs/Threat_Abatement_Plan_Plaque_Minnow.pdf

Page LM, Burr BM, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston, 432 pp.

Pethiyagoda R, 1991. Freshwater fishes of Sri Lanka. The Wildlife Heritage Trust of Sri Lanka, Colombo, 362 pp.

Piyakarnchana T, 1989. Exotic aquatic species in Thailand. In: De Silva SS, ed. Exotic aquatic organisms in Asia. Proceedings of the Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fish. Soc. Spec. Publ, 3. Manila, Philippines: Asian Fisheries Society, 119-124.

Pyke GH, 2005. A review of the biology of Gambusia affinis and G. holbrooki. Reviews in Fish Biology and Fisheries, 15(4):339-365. http://www.springerlink.com/link.asp?id=100215

Reshetnikov YS, Bogutskaya NG, Vasil’eva ED, Dorofeeva EA, Naseka AM, Popova OA, Savvaitova KA, Sideleva VG, Sokolov LI, 1997. An annotated check-list of the freshwater fishes of Russia. Journal of Ichthyology, 37:687-736.

Setler EM, Boynton WR, Wood KV, Zion HH, Lubbers L, Mountford NK, Frere P, Tucker L, Mihursky JA, 1980. Synopsis of biological data on striped bass, Morone saxatilis (Walbaum). NOAA Technical Report NMFS Circular 433, FAO Synopsis No. 121.

Shrestha TK, 1990. Resource ecology of the Himalayan waters. Kathmandu, Nepal: Curriculum Development Centre, Tribhuvan University, 645 pp.

Thys van den Audenaerde DFE, 1994. Introduction of aquatic species into Zambian waters, and their importance for aquaculture and fisheries. Aquaculture for Local Community Development Programme, ALCOM Field Document No. 24, 29 pp.

US Fish and Wildlife Service, 1982. In: Clear Creek Gambusia (Gambusia heterochir) Recovery Plan. US Fish and Wildlife Service, 29 pp..

US Fish and Wildlife Service, 1994. In: Big Spring Spinedace (Lepidomeda mollispinis pratensis) Recovery Plan. US Fish and Wildlife Service, 51 pp.. http://ecos.fws.gov/docs/recovery_plan/940120.pdf

US Fish and Wildlife Service, 1998. In: Gila Topminnow, Poeciliopsis occidentalis occidentalis, Revised Recovery Plan. US Fish and Wildlife Service, 83 pp..

US Fish and Wildlife Service, 2006. In: Final Recovery Plan for the Newcomb's Snail (Erinna newcombi). US Fish and Wildlife Service, 61 pp.. http://ecos.fws.gov/docs/recovery_plan/060918b.pdf

US Fish and Wildlife Service, 2008. In: Independence Valley Speckled Dace (Rhinichthys osculus lethoporus). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 27 pp..

US Fish and Wildlife Service, 2008. In: The Virgin River Fish Woundfin (Plagopterus argentissimus) Virgin River chub (Gila seminuda). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 71 pp..

US Fish and Wildlife Service, 2013. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Gila nigra. US Fish and Wildlife Service, 37 pp.. http://ecos.fws.gov/docs/candidate/assessments/2013/r2/E0AH_V01.pdf

US Fish and Wildlife Service, 2013. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Gila robusta. US Fish and Wildlife Service, 79 pp.. http://ecos.fws.gov/docs/candidate/assessments/2013/r2/E02Z_V01.pdf

US Fish and Wildlife Service, 2013. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Hyla wrightorum. US Fish and Wildlife Service, 34 pp.. https://ecos.fws.gov/docs/candidate/assessments/2014/r2/D03S_V02.pdf

US Fish and Wildlife Service, 2013. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Iotichthys phlegethontis. US Fish and Wildlife Service, 47 pp.. http://ecos.fws.gov/docs/candidate/assessments/2013/r6/E02U_V01.pdf

US Fish and Wildlife Service, 2013. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Pyrgulopsis morrisoni. US Fish and Wildlife Service, 17 pp.. http://ecos.fws.gov/docs/candidate/assessments/2013/r2/G059_I01.pdf

US Fish and Wildlife Service, 2014. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Ambrysus funebris. US Fish and Wildlife Service, 17 pp.. http://ecos.fws.gov/docs/candidate/assessments/2014/r8/I0T8_I01.pdf

US Fish and Wildlife Service, 2014. In: U.S. Fish and Wildlife Service species assessment and listing priority assignment form: Megalagrion xanthomelas. US Fish and Wildlife Service, 14 pp.. http://ecos.fws.gov/docs/candidate/assessments/2014/r1/I063_I01.pdf

USGS, 2003. Non indigenous aquatic species database. US Geological Survey Online, USA. Online. http://nas.er.usgs.gov/. Accessed on 27 February 2004.

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

Willis K, Ling N, 2000. Sensitivities of mosquitofish and black mudfish to a piscicide: could rotenone be used to control mosquitofish in New Zealand wetlands? New Zealand Journal of Zoology, 27(2):85-91.

Xie Y, 2001. Invasive species in China - An overview. In: Balakrishna P, ed. Report of Workshop on Alien Invasive Species, GBF-SSEA. Colombo, Sri Lanka: IUCN Regional Biodiversity Programme, 20-46.

Yamamoto MN, 1992. Occurrence, distribution and abundance of accidentally introduced freshwater aquatic organisms in Hawaii. State of Hawaii, Federal Aid in Sportfish Restoration, Dingell-Johnson JOR. Freshwater Fisheries Research and Surveys, Project No. F-14-R-16.

Yamamoto MN, Tagawa AW, 2000. Hawai’i’s native and exotic freshwater animals. Mutual Publishing, Honolulu, Hawaii, 200 pp.

Distribution References

Anon, 1988. FAO Fisheries Technical Paper. [ed. by Welcomme R L]. Rome, Italy: Food and Agriculture Organization of the United Nations. x + 318 pp.

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

CABI, Undated. Compendium record. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

FAO, 1997. FAO Database on Introduced Aquatic Species., Rome, Italy: Food and Agricultural Organization of the United Nations.

Links to Websites

Contributors

09/01/2010 Updated by:

Vicki Bonham, CABI, Nosworthy Way, Wallingford, OX10 8DE, UK

Main Author
Sunil Siriwardena
Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK

Distribution Maps