Invasion History

First Non-native North American Tidal Record: 1977
First Non-native West Coast Tidal Record: 1977
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Sailfin Mollies (Poecilia latipinna) are native in freshwater, brackish and marine habitats from the Cape Fear River, North Carolina, to Veracruz, Mexico. They breed in marine and freshwater environments, but rarely occur more than 200 km from marine waters in their native range (Page and Burr 1991). They are widely reared and sold as an aquarium fish, and have established introduced populations in coastal habitats in California, Hawaii, Guam, the Philippines, Queensland, Australia, and the Bahamas. They have also been released for insect biocontrol and raised as a baitfish for tuna (Randall1987; Swift et al. 1993; Lever 1996; Koutsikos et al. 2018).

North American Invasion History:

Invasion History on the West Coast:

Sailfin Mollies (Poecilia latipinna) were found in 1977 in an un-named slough in Oxnard, California, near Port Hueneme (Swift et al. 1993). They were also found in Ballona Marsh, in Santa Monica, CA (1990, Swift et al. 1993; Torchin 2010); and in Sweetwater Marsh National Wildlife Refuge, on San Diego Bay in 1989 (San Diego Bay) (1989, Williams et al. 1998). These populations are considered established (Torchin 2010; Williams et al. 1998; USGS Nonindigenous Aquatic Species Program 2018).

Invasion History on the East Coast:

Invasion History on the Gulf Coast:

Invasion History in Hawaii:

Sailfin Mollies (Poecilia latipinna) were first introduced into Moanalua Stream, in Oahu in 1985 for mosquito control. They were unsuccessful as a mosquito control, feeding mostly on algae and benthic invertebrates. Sailfin Mollies are now established in brackish lagoons in Oahu, Hawaii, Maui, Kaui, and Molokai (Brock 1960; Randall 1987; Carlton and Eldredge 2009). It is abundant in Pearl Harbor (Coles et al. 1999). They have been found at salinities of 0-27 PSU (Carlton and Eldredge 2009). They were also introduced as baitfish for a Skipjack Tuna (Katsuwonus pelamis) fishery, but this transplant to Kauai was unsuccessful (Randall 1987).

Invasion History Elsewhere in the World:

Sailfin Mollies (Poecilia latipinna) have been introduced to many locations in the interior of North America, including hot springs in Alberta and Montana, and desert springs, streams, and reservoirs in California, Nevada, Utah, Colorado, and New Mexico, and inland rivers in Texas (Lever 1996; Dill and Cordone 1997; Moyle 2002; USGS Nonindigenous Aquatic Species Program).

In the Caribbean, Sailfin Mollies have been reported from Puerto Rico. One record (of 4) was near the mouth of the Canovanillas River, on the north shore of the island (2007, USGS Nonindigenous Aquatic Species Program 2018). The Sailfin Molly is also established in salt lakes on the Bahamas (1972, Barton 1995).Other Caribbean records are in the Dominican Republic and Venezuela (Koutsikows et al. 2018). In South America, Koutsikos et al. (2018) indicate records from the Pacific coast of Colombia and Brazil. There are multiple records from the Middle East, including coastal parts of the Persian Gulf, and the Shaat-Al-Arab estuary (2014, Esmaeilei et al. 2017; Koutsikos et al. 2018). Records in Asia include India, Thailand, Singapore, and China (Lever 1996; Kunlapapuk et al. 2015; Koutsikos et al. 2018). In the Philippines, it inhabits brackish ponds, where it was introduced for mosquito control (Lever 1996).

Sailfin Mollies were introduced to Australia around 1968 to creeks in Hervey Bay and in Sandgate Lagoon, Queensland, Australia, in 1969 as aquarium releases. Early reports refer to 'Black Mollies', so some of these fish may have been a cultivated color strain (Lever 1996). In Australia, Sailfin Mollies are legally treated as a pest species, and can be kept in aquaria, but cannot be used as bait or returned to the wild (Museums Victoria 2018). In New Zealand, it is found in geothermally heated Lake Taupo, where it was first released in 1967, but is unlikely to spread into colder waters (Lever 1967). On smaller Pacific islands they are established in Guam, Fiji, and the Northern Mariana Islands (Maciolek 1984; Lever 1996; Koutsikos et al. 2018).

In 2010, a population of Sailfin Mollies was discovered in a brackish, geothermally heated lagoon, Lake Vouliagmeni, near Athens, Greece. Many of the fish had black pigmentation, indicating a recent aquarium introduction, while others had a 'wild-type' coloration. This is the first established population of the Sailfin Molly in Europe (Koutsikos et al. 2017).


Sailfin Mollies (Poecilia latipinna) are small live-bearing fish that inhabits fresh, brackish, and marine waters. Fishes in the family Poecilidae have dramatic sexual dimorphism, with the male's anal fin elongated into an intromittent organ called the gonopodium (an intromittent organ is a specialized external male organ used to deliver sperm during copulation). Poecilid fishes have the mouth upturned and the head flattened for feeding at the surface. They have a single dorsal fin and lack dorsal and anal fin spines. They also lack a lateral line. A large male has a large sail-like dorsal fin. Both sexes have a small head, a deep, compressed body, and a thick caudal peduncle and 13 to 16 dorsal rays. In females the anterior edge dorsal fin originates at a point along the length of the body above the anterior edge of the anal fin. Adults reach 150 mm, but a common length is ~35 mm. Adults are olive dorsally, and white to yellowish ventrally, with iridescent yellow flecks on their sides. There are five rows of black spots along the sides, and several rows of brown spots on the caudal and dorsal fins. The large dorsal fin of the males is bright blue towards the top with an orange edge to the dorsal fin. Breeding in the aquarium industry has produced cultivated varieties with black spots, all black, multiple colors, and modified fins, called Lyretail Mollies (Robins et al. 1986; Page and Burr 1991; Rohde et al. 1994; Froese and Pauly 2018)


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Chordata
Subphylum:   Vertebrata
Superclass:   Osteichthyes
Class:   Actinopterygii
Subclass:   Neopterygii
Infraclass:   Teleostei
Superorder:   Acanthopterygii
Order:   Cyprinodontiformes
Suborder:   Cyprinodontoidei
Family:   Poeciliidae
SubFamily:   Poeciliinae
Genus:   Poecilia
Species:   latipinna


Limia matamorensis (Girard, 1858)
Limia poeciloides (Girard, 1858)
Mollienesia latipinna (Lesueur, 1821)
Poecilia lineolata (Girard, 1858)
Poecilia multilineata (Lesueur, 1821)

Potentially Misidentified Species

Poecilia mexicana
Poecilia mexicana (Shortfin Molly) is native to the Atlantic Slope of Mexico from the Rio San Juan to Guatemala (Page and Burr 1991). It is established at hot springs in Montana, Idaho, and Colorado, and desert sites in Arizona, California, and Nevada (USGS Nonindigenous Aquatic Species Program 2018). The California records are in streams and canals, leading to the Salton Sea and to the lower Colorado River (Dillon and Cordone 1991).



Sailfin Mollies (Poecilia latipinna) are live-bearing fish that breed in freshwater, brackish, marine, and hypersaline environments. They have also been seen more than 200 km from marine waters in their native range, but this is rare (Page and Burr 1991). Females brood their eggs and release fully developed juveniles from a brood pouch. Livebearers (Poecilidae) are strongly sexually dimorphic, with small males adapted for internal fertilization. Courtship involves displays by the male showing off their expanded dorsal fin. Gestation takes ~28 days, and females produce 10-141 young, which are ~12 mm at birth. The young fish mature rapidly and probably live for 2-3 years (Rohde et al. 1994; Froese and Pauly 2018).

Sailfin Mollies inhabit a wide range of environments from freshwater to hypersaline waters including, caves, canals, ditches, springs, lagoons, mangroves, marshes and swamps (Page and Burr 1991; Rohde et al. 1994; Nordlie 2006; Froese and Pauly 2018). Their native and introduced ranges are limited by low winter temperatures (~7.7 C), and a high temperature requirement for reproduction (22 C) (Froese and Pauly 2018; Koutsikos et al. 2018). Their preferred temperature range is 20-30 C, but they can tolerate extremes up to 41 C (Nordlie 2006; Bierbach et al. 2010). At the same time, this fish has a very wide salinity range, from freshwater to hypersaline conditions, 0-80 PSU (Simmons 1957; Nordlie 2006). Sailfin mollies prefer still or slow-flowing water that is densely vegetated. They often swim and feed near the surface. In the Carolinas, they occur only in Spartina marshes, which also seems to be their preferred habitat in California (Page and Burr 1991; Swift et al. 1993; Rohde et al. 1994). In Sweetwater Marsh, San Diego Bay, Sailfin Mollies especially used salt marsh pannes (shallow depressions) and the marsh surface (Williams 1998). Sailfin Mollies are tolerant of low oxygen, especially when they have access to the oxygenated water just below the surface (Nordlie 2006). They are omnivores, feeding on algae, vegetation, benthic invertebrates, mosquito larvae, and detritus (Randall 1987; Rohde et al. 1994). This fish is vulnerable to fish and bird predators, but compensates by rapid reproduction.

Trophic Status:




General HabitatGrass BedNone
General HabitatSwampNone
General HabitatNontidal FreshwaterNone
General HabitatTidal Fresh MarshNone
General HabitatSalt-brackish marshNone
General HabitatUnstructured BottomNone
Salinity RangeLimnetic0-0.5 PSU
Salinity RangeOligohaline0.5-5 PSU
Salinity RangeMesohaline5-18 PSU
Salinity RangePolyhaline18-30 PSU
Salinity RangeHyperhaline40+ PSU
Tidal RangeSubtidalNone
Vertical HabitatNektonicNone

Life History

Tolerances and Life History Parameters

Minimum Temperature (ºC)7.7Bierbach et al. 2010, Critical Temperature Minimum
Maximum Temperature (ºC)41Bierbach et al. 2010, Critical Temperature Maximum
Minimum Salinity (‰)0This species occurs and breeds in freshwater as well as alt (Page and Burr 1991).
Maximum Salinity (‰)80Field, Lagune Madre, Texas (Simmons1957)
Minimum Dissolved Oxygen (mg/l)1Nordlie 2006, Field, with our acess to the surface
Minimum Reproductive Temperature22Daewa 1991, citied by Koutsikos et al. 2018
Minimum Reproductive Salinity0This species occurs and breeds in freshwater (Page and Burr 1991).
Maximum Length (mm)150Page and Burr 1991
Broad Temperature RangeNoneWarm Temperate-Tropical
Broad Salinity RangeNoneNontidal Limnetic-Hyperhaline

General Impacts

Sailfin Mollies (Poecilia latipinna) can colonize a wide range of habitats in warm-temperate and subtropical climates, and is especially capable of utilizing modified habitats, such as ditches, canals, water tanks, and disturbed marshes (Randall 1987; Swift et al. 1993). They are economically important as popular aquarium fish, which are sold in wild-type color and morphology, but also in black, spotted, yellow, and orange color morphs, and with modified fins (Lyretail) varieties (Froese and Pauly 2018). Some introductions were made for mosquito biocontrol, but these omnivorous fish proved to be ineffective mosquito-larva predators (Randall 1987). Sailfin Mollies have shown aggressive behavior towards other fishes, such as California Killifish (Fundulus parvipinnis), Bahama Pupfish (Cyprinodon laciniatus) (Barton 1995; Williams et al. 1998), and desert pupfishes (Cyprinodon spp.).

Economic Impacts-

As noted above, Sailfin Mollies are a popular aquarium fish, sold and bred around the world. Websites indicate that Thailand is an important location for breeding and export of Sailfin Mollies and other tropical fishes. As a result, Sailfin Mollies are established there (Kunlapapuk et al. 2015).

Ecological Impacts-

Sailfin Mollies have a wide range of tolerances, and can colonize a wide range of habitats, including those inhabited by more specialized and localized species. They can be aggressive towards other species, such has California Killifish (Fundulus parvipinnis), Bahamas Pupfish (Cyprinodon laciniatus), and the Desert Pupfish Cyprinodon macualrius (Barton 1995; Dill and Cordone 1997; Williams et al. 1998). But young Sailfish Mollies also provide an extra food source tor the native fishes, such as California Killifish, which grew faster in the presence of Sailfin Mollies (Torchin 2010).

Competition- Male Sailfin Mollies in aquaria showed aggressive courtship behavior toward California Killifish (Fundulus parvipinnis) (Williams et al. 1998). They are also believed to be competing with the globally threatened Bahamas Pupfish (Cyprinodon laciniatus) in the Bahama (Barton 1999) and the Desert Pupfish Cyprinodon macularius in southwestern US desert waters (Schoenherr 1988). Competitive effects with California Killifish were not seen in Ballona Marsh, California (Torchin 2010).

Regional Impacts

CAR-VNoneEcological ImpactCompetition
Sailfin Mollies (Poecilia latipinna) together with Mozambique Tilapia (Oreochromis mossambicus) is reportedly threatening native, globally rare Cyprinodon laciniatus in salt lakes in the Bahamas (Barton 1999).
NEP-VIPt. Conception to Southern Baja CaliforniaEcological ImpactFood/Prey
Sailfin Mollies (Poecilia latipinna) provided an unexpected benefit for the native California Killifish (Fundulus parvipinnis) in Ballona Marsh. In experiments, the native killifish showed increased growth in the presence of female mollies. This increased growth apparently resulted from predation on newborn mollies, which are born viviparously, and apparently constitute a significant food item (Torchin 2010).
P060Santa Monica BayEcological ImpactFood/Prey
The native California Killifish (Fundulus parvipinnis) grew faster in the presence of the Sailfin Molly (Poecilia latipinna), because the newborn young of the viviparous Molly provided a novel food source (Torchin 2010).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-VII Cape Hatteras to Mid-East Florida 0 Native Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 0 Native Estab
NEP-VI Pt. Conception to Southern Baja California 1977 Def Estab
EAS-III None 1968 Def Estab
AUS-XII None 1978 Def Estab
SP-XXI None 1905 Def Estab
SP-XII None 0 Def Estab
P020 San Diego Bay 1989 Def Estab
P062 _CDA_P062 (Calleguas) 1977 Def Unk
P060 Santa Monica Bay 1999 Def Estab
CAR-V None 1972 Def Estab
MED-VI None 2010 Def Estab
EAS-I None 2015 Def Estab
CAR-IV None 2007 Def Estab
AG-2 None 2015 Def Estab
MED-V None 2017 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


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Barton, Michael (1999) Threatened fishes of the world: Cyprinodon laciniatus Hubbs & Miller, 1942 (Cyprinodontidae)., Environmental Biology of Fishes 55: 422

Coles, S. L.; DeFelice, R. C.; Eldredge, L. G.; Carlton, J. T. (1999b) Historical and recent introductions of non-indigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands., Marine Biology 135(1): 147-158

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Jacobs, Jade; Rollwagen-Bollens, Gretchen; Bollens, Stephen M. (2022) Feeding dynamics of the invasive calanoid copepod Pseudodiaptomus inopinus in two northeast Pacific estuaries, Aquatic Ecology 31: 49-64

Jacobs, Jade; Rollwagen-Bollens, Gretchen; Bollens, Stephen M. (2022) Feeding dynamics of the invasive calanoid copepod Pseudodiaptomus inopinus in two northeast Pacific estuaries, Aquatic Ecology 31: 49-64

Lever, Christopher (1996) Naturalized fishes of the world, Academic Press, London. Pp. <missing location>

Maciolek, J. A. (1984) Exotic fishes in Hawaii and other islands of Oceania., In: Courtenay, W. R., Jr., and Stauffer, J. R., Jr.(Eds.) Distribution, Biology, and Management of Exotic Fishes. , Baltimore, MD. Pp. 131-161

MacKenzie, Richard Ames; Bruland, Gregory L. (2012) Nekton communities in Hawaiian coastal wetlands: the distribution and abundance of introduced fish species, Estuaries and Coasts 35: 212-226

Martin, Shannon B.; Hitch, Alan T.; Purcell, Kevin M.; Klerks, Paul L.; Leberg, Paul L. (2009) Life history variation along a salinity gradient in coastal marshes, Aquatic Biology 8: 15-28

7/29/2022 For the first time, live invasive green crabs have been found in Alaska. Radio story, web page

Moyle, Peter B. (1976) Fish introductions in California: History and impact on native fishes., Biological Conservation 9: 101-118

Page, Lawrence M.; Burr, Brooks M. (1991) Freshwater Fishes: North America North of Mexico, Houghton-Mifflin, Boston. Pp. <missing location>

Queiroz, Romilda Narciza Mendonça; Pereira Dias, Thelma Lúcia; Batista, Raniele; da Silva, Patrícia Mirella (2021) Reproduction and population dynamics of the invasive bivalves Mytilopsis sallei and Isognomon bicolor on the Northeast coast of Brazil, Zoology 153(126038): Published online

Queiroz,Romilda Narciza Mendonça; Dias, Thelma Lúcia Pereira ; b, Batista, Raniele; da Silva, Patrícia Mirella (2022) Reproduction and population dynamics of the invasive bivalves Mytilopsis sallei and Isognomon bicolor on the Northeast coast of Brazil, Zoology 153(126039): Published online

Quinn, Emma A.; Thomas, Jessica E.; Malkin, Sophie H.; Eley, Molly-Jane; Coates, Christopher J.; Rowley, Andrew F. (2022) nvasive slipper limpets Crepidula fornicata are hosts for sterilizing digenean parasites, Parasitology 149: 811–819.

Robins, C. Richard; Ray, G. Carleton; Douglass, John; Freund, Rudolf 1943 (1986) <missing title>, Houhgton Mifflin, Boston. Pp. <missing location>

Rohde, Fred C.; Arndt, Rudolf G.; Lindquist, David G.; Parnell, James F. (1994) <missing title>, Universilty of North Carolina Press, Chapel Hill. Pp. <missing location>

Shiraki, Shoki; Kakui, Keiichi (2022) Observations on Predation in Paranthura japonica Richardson, 1909 (Isopoda: Cymothoida: Paranthuridae), Zoological Science 39: 270-274

Simmons, Ernest G. (1957) An ecological survey of the Upper Laguna Madre of Texas, Publications in Marine Science of the University of Texas 4(2): 156-200

Swift, Camm C., Haglund, Thomas R., Ruiz, Mario, Fisher, Robert N. (1993) The status and distribution of the freshwater fishes of southern California, Bulletin of the Southern California Academy of Sciences 92(3): 101-167

Torchin, Mark E. (2010) Native fish grows faster in the presence of a potential introduced competitor, Aquatic Invasions 5(2): 163-167

2003-2015 Nonindigenous Aquatic Species Database. Gainesville, FL.

Williams, Gregory D., Desmond, Julie S., Zedler, Joy B. (1998) Extension of 2 nonindigenous fishes, Acanthogobius flavimanus and Poecilia latipinna, into San Diego Bay marsh habitats, California Fish and Game 84(1): 1-17