Poecilia is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes.[2] These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide (H
2S)[3] and a population of P. mexicana lives in caves (other populations of this species are surface-living).[4]
Poecilia | |
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Male sailfin molly (P. latipinna) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Cyprinodontiformes |
Family: | Poeciliidae |
Subfamily: | Poeciliinae |
Tribe: | Poeciliini |
Genus: | Poecilia Bloch & J. G. Schneider, 1801 |
Type species | |
Poecilia vivipara Bloch & J. G. Schneider, 1801
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Species | |
See text. | |
Synonyms[1] | |
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Some common and widespread species are often kept as aquarium fish, while other have very small ranges and are seriously threatened.[3] Species in Poecilia are called mollies (e. g. P. sphenops) or guppies (e. g. P. reticulata) depending on body shape.
Micropoecilia has been proposed to be included as a subgenus of Poecilia.[5]
Poecilia was first proposed as a genus in 1801 by the German naturalists Marcus Elieser Bloch and Johann Gottlob Theaenus Schneider when the described Poecilia vivipara as a new species. P. vivipara was subsequently designated as the type species of the genus by Pieter Bleeker in 1864.[6] It is the type genus of the subfamily Poeciliinae and of the family Poeciliidae.[7] Poecilia refers to the Greek word poikilos, which means "variegated" or "speckled", an allusion to the coloration and pattern of the type species, as well as that of and other related fishes, such as Fundulus heteroclitus which Bloch & Schneider classified in this genus.[8]
Fish of this genus have extremely variable coloration and have been selectively bred to create many different varieties. The most commonly kept species are guppies (P. reticulata), mollies (P. sphenops or P. latipinna), and Endler's livebearers (P. wingei). Members of the genus readily hybridize with each other and so most commercially offered fish are hybrids (with guppies having some Endler, and mollies being a mix of common and sailfin mollies).[9]
They are easy to sex as males have a prominent gonopodium, a modified anal fin used to inseminate females. They mature quickly and breed readily, with females giving birth to a dozen or more fry every month.[10] Some poecilids are cannibalistic and will eat any of their fry that are unable to flee in time (with females often eating the fry they just gave birth to, especially in a cramped aquarium setting).
The 41 currently recognized species in this genus are:[11][12]
If Poecilia in the wider sense is used then the species would be divided up into subgenera as follows:[8]