The sailfin molly (Poecilia latipinna) is a species of fish of the genus Poecilia. They inhabit fresh, brackish, salt, and coastal waters from North Carolina to Texas and the Yucatán Peninsula of Mexico. Taxonomy The sailfin molly was originally described in 1821 as Mollienesia latipinna by the naturalist Charles Alexandre Lesueur, who based his description upon specimens from freshwater ponds in the vicinity of New Orleans, Louisiana. However, Lesueur described other collections of the sailfin molly as Mollienesia multilineata in 1821, the same year in which he described M. latipinna. This conflict created confusion and eventually necessitated a ruling by the International Commission on Zoological Nomenclature (ICZN). In 1959, the ICZN placed precedence on the name Mollienesia latipinna Lesueur 1821. In a landmark definitive work on poeciliid fishes, Donn Rosen and Reeve Bailey (1959) noted the priority of Poecilia by Marcus Elieser Bloch and Johann Gottlob Schneider (1801) with regards to Mollienesia by Lesueur (1821), thereby relegating Mollienesia to the synonymy of Poecilia. Names Some names for the sailfin molly in other languages include Breitflossenkärpfling (German), seilfinnemolly (Norwegian), zeilvinkarper (Dutch), leveäevämolli (Finnish), molinezja szerokopłetwa (Polish), bubuntis (Tagalog), and molliénésie á voilure or simply "molly voile" (French). Some confusion occurs with the Yucatan molly, P. velifera. While most names that contain a "sail" element refer to the present species, the German Segelkärpfling, the Latin velifera, and possibly others are used for the Yucatan molly. The French terms are used for both species indiscriminately. The sailfin molly is also commonly sold in aquarium stores under the name "molly". Geographical distribution The sailfin molly is found in freshwater habitats from North Carolina to Texas and the Yucatán Peninsula of Mexico. Preferring marshes, lowland streams, swamps, and estuaries, the sailfin molly is very common in peninsular Florida. Nonindigenous populations are established in New Zealand, in the western U.S., and Hawaii. Sailfin mollies introduced to California have caused a decline in populations of the federally protected and endangered desert pupfish (Cyprinodon macularius). It is also invasive to Iraq, threatening many killifish endemic to the basin of the Tigris and Euphrates. It was introduced in the 1920s to the Banff Hot Spring, in Banff National Park Habitat Sailfin mollies are most commonly observed at the shallow surface waters along the edges of marshes, lowland streams, ponds, swamps, estuaries and even ephemeral water bodies such as roadside ditches. Small to large aggregations of the species are most