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Gambusia affinis

Iku Kai-namu

Western Gambusia

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General Information

COMMON NAMES: Western Gambusia, Western Mosquitofish, Western Topminnows, Texas Mosquitofish; German Koboldkärpfling; French Gambusie

TRADITIONAL NAMES: Iku Kai-namu (MG)

GLOBAL DISTRIBUTION: NATIVE n.Mexico - Mississippi; EXOTIC EXOTIC widely (incl. NZ, Cooks, Hawai‘i)

COOK ISLANDS STATUS: Introduced - Recent, Naturalised; Recent, Naturalised. S.Group, common. PLUS: S.Group, common.; Freshwater, ponds - streams

SIGNIFICANCE LIST: Biocontrol - released pre-1960

Cook Islands Distribution

View Distribution Map

Southern Group: Present Makatea: ?
RR	MG	AT	MK	MT	AK	PL	TK	MN
+++	P

Northern Group: ?
TN	MH	RK	PK	NS	SW

Key to Symbols

blank	no data
-	absent	L	localised
X	extinct 'naturally'	W	widespread
XQi	quarantine intercepted	R	recent
XQe	eradicated	?	query preceding category
P	present	T?	taxonomic query
S	seasonal	nn	present, said to have no name
O	occasional	?1	present, name not investigated
++++	very common	?2	presence not verified, no name recorded
+++	common	N/A	absent, name not expected
++	uncommon
+	rare
Cook Islands islands: RR =Rarotonga, MG = Mangaia, AT =‘Ātiu, MK=Ma‘uke, MT=Miti‘āro, AK=Aitutaki, PL=Palmerston, PN=Penrhyn, MN=Manuae, TK=Takūtea, TN=Tongareva (TS=Tongaleva Spoken, TW=Tongareva Written, they say "el" but write "r"), MH=Manihiki, RK=Rakahanga, PK=Pukapuka, NS=Nassau, SW=Suwarrow. After a Polynesian name: ^=orthography query. Countries and other: FIJ=Fiji, WT=Wallis & Futuna, SAM=Samoa, TON=Tonga, NIU=Niue, CK=Cook Islands, CKM=Cook Islands Māori, FP=French Polynesia, AUS=Australs, SOC=Societies, TAH=Tahiti, TUA=Tuamotus, MQS=Marquesas, MNG=Mangareva, PIT=Pitcain group, EAS=Easter Island, HAW=Hawai‘i, NZ=New Zealand, NZM=New Zealand Māori

Scientific Taxonomy

Gambusia affinis (Baird & Girard, 1853)
SYNONYMS: Gambusia affinis affinis; Heterandria affinis [O]; Gambusia affinis affinis

TAXONOMY: ANIMALIA; CHORDATA; GNATHOSTOMATA (Jawed Vertebrates); PISCES; OSTEICHTHYES; Cyprinodontiformes; Cyprinodontoidei; POECILIIDAE, Poeciliinae

More Information

SIGNIFICANCE NOTES -
POSITIVE SIGNIFICANCE: Biocontrol - released pre-1960. Comments: Biocontrol - released pre-1960. A report by Euan Young (2002), on the mosquitoes of Rarotonga, concluded that if Gambusia are plentiful in swamps and pools they effectively control the two Culex mosquitoes that breed in those habitats. They have no effect on the two Aedes species that breed in small natural and artificial containers.. Comments: One of world's top 100 invasive alien species [ISSG,2001].

GENERAL NOTE: The Western Gambusia (Gambusia affinis) was introduced to Hawai‘i around 1905 from Texas, and later to New Zealand. The Cook Islands fish probably came from New Zealand. In contrast, the Gambusia in Australia came from Georgia via Italy in 1926 and it is the Eastern Gambusia (Gambusia holbrooki, formerly Gambusia affinis holbrooki). The two species are separated by microscopic examination of the male reproductive structure (=gonopodium), and Gambusia holbrooki typically has Dorsal fin rays 7 (vs. 6) and Anal fin rays 10 (vs. 9). [after Loyd & Tomasov (1985), and Loyd pers.comm. 1/2005]

Vouchers & References

Vouchers:
Rarotonga: Welcomme1988, FAO Fish. Tech. Pap. #294.

References:
Special Reference: Loyd, L. & Tomasov, J. (1985) Taxonomic Status of the Mosquitofish, Gambusia affinis, in Australia, Aust. J. Mar. Freshw. Res 36:447-51. Welcomme, R. International Introductions of Inland Aquatic Species. FAO Fish. Tech. Pap. #204.

Data Update History (information):
zTX, zB02, zM05a

Web Resources

Citation Information

McCormack, Gerald (2007) Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga. Online at http://cookislands.bishopmuseum.org.
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