The Poeciliidae are a family of freshwater fishes of the order Cyprinodontiformes, the tooth-carps, and include well-known live-bearing aquarium fish, such as the guppy, molly, platy, and swordtail. The original distribution of the family was the Southeastern United States to north of Río de la Plata, Argentina, and Africa, including Madagascar. Due to release of aquarium specimens and the widespread use of species of the genera Poecilia and Gambusia for mosquito control, though, poeciliids can today be found in all tropical and subtropical areas of the world. In addition, Poecilia and Gambusia specimens have been identified in hot springs pools as far north as Banff, Alberta.
Gambusia is a large genus of viviparous fish in the family Poeciliidae. Gambusia contains over 40 species, most of which are principally found in freshwater habitats, though some species may also be found in brackish or saltwater habitats. The type species is the Cuban gambusia, G. punctata. The greatest species richness is in Mexico, Texas, and the Greater Antilles, but species are also found elsewhere in the eastern and southern United States, the Bahamas, Central America, and Colombia. Gambusia species are often called topminnows, or simply gambusias; they are also known as mosquitofish, which, however, refers more specifically to two species, G. affinis and G. holbrooki, which are often introduced into ponds to eat mosquito larvae. As a consequence, they have been introduced widely outside their native range, and frequently become invasive, threatening local species. They are only occasionally kept in aquariums, due to their relative lack of color and the highly aggressive nature of the aforementioned mosquitofish species.
Xiphophorus is a genus of euryhaline and freshwater fishes in the family Poeciliidae of order Cyprinodontiformes, native to Mexico and northern Central America. The many Xiphophorus species are all called either platyfish or swordtails. The type species is X. hellerii, the green swordtail. Like most other new world Poeciliids, platies and swordtails are live-bearers that use internal fertilization and give birth to live young instead of laying eggs like the bulk of the world's fishes. The name Xiphophorus derives from the Greek words ξίφος (dagger) and φόρος (bearer), referring to the gonopodium on the males. All are relatively small fishes, which reach a maximum length of 3.5–16 cm (1.4–6.3 in) depending on the exact species involved.
Poecilia is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. 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 and a population of P. mexicana lives in caves.
Catostomus is a genus of fish belonging to the family Catostomidae, commonly known as suckers. Most members of the genus are native to North America, but C. catostomus is also found in Russia. Fish from different species of the genus are known to readily hybridize with each other.
Limia is a genus of livebearing fishes belonging to the Cyprinodontiform family Poeciliidae, which includes other livebearers such as platys, swordtails, guppies and mollies. They are found in fresh and brackish water. Of the 21 described Limia species, 17 are endemic to Hispaniola, one is found on both Hispaniola and Jamaica, and the Cayman Islands, Cuba, and Venezuela have an endemic species each. Limia are popular in aquaria among more advanced hobbyists.
Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization by sperm. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis.
Notropis is a genus of freshwater fish in the family Cyprinidae. They are known commonly as eastern shiners. They are native to North America, and are the continent's second largest genus.
Cyprinella is a genus of fish in the family Cyprinidae, the carps and minnows. They are known as the satinfin shiners. They are native to North America, and some are among the most common freshwater fish species on the eastern side of the continent. Conversely, several Cyprinella species with small distributions are threatened and the Maravillas Creek subspecies of the red shiner is extinct.
Allotoca is a genus of splitfins that are endemic to west-central and southwest Mexico, where restricted to the Lerna–Chapala–Grande de Santiago, Ameca and Balsas river basins, as well as various endorheic lake basins in Michoacán and Jalisco. All Allotoca species are seriously threatened.
Girardinichthys is a genus of splitfins that are endemic to Mexico. These highly threatened fish are native to the upper Lerma and Balsas basins, as well as water systems in the Valley of Mexico. Through man-made channels G. viviparus has been able to spread to the upper Pánuco River basin. These small fish reach up to 6.5 cm (2.6 in) in length. The name of this genus honours the American herpetologist and ichthyologist Charles Girard (1822-1895).
Poeciliopsis monacha, or the headwater livebearer, is a species of freshwater fish in the family Poeciliidae. It is endemic to Mexico.
Heterandria is a genus of livebearing fishes within the family Poeciliidae. Most species occur in Guatemala and its surroundings, particularly Mexico, but the midget livebearer (H. formosa) comes from the southeastern United States.
Heroini is a fish tribe from the Cichlasomatinae subfamily in the cichlid family. All cichlids native to the Greater Antilles, United States, Mexico and northern Central America are members of this tribe. It also includes most cichlid species in southern Central America and several species from South America. A large percentage of its species were formerly placed in the genus Cichlasoma, but have since been moved to other genera.
The Yaqui topminnow is a species of fish in the family Poeciliidae. Its scientific name is Poeciliopsis sonoriensis; it is also sometimes considered a subspecies of Poeciliopsis occidentalis as P. o. sonoriensis. This fish is native to Mexico and the United States, with a few native and introduced populations persisting in Arizona in the United States, and a number of populations still extant in northern Sonora, Mexico.
Profundulus is a genus of fish in the family Profundulidae endemic to Mexico and northern Central America. According to many authorities, including Fishbase this is the only genus in the Profundulidae but workers have split the genus and raised a second genus Tlaloc.
Atherinella is a genus of Neotropical silversides from freshwater, brackish and marine habitats in Mexico, Central America and South America.
Pregnancy has been traditionally defined as the period of time eggs are incubated in the body after egg-sperm union. Although the term often refers to placental mammals, it has also been used in the titles of many international, peer-reviewed, scientific articles on fish, e.g. Consistent with this definition, there are several modes of reproduction in fish, providing different amounts of parental care. In ovoviviparity, there is internal fertilization and the young are born live but there is no placental connection or significant trophic (feeding) interaction; the mother's body maintains gas exchange but the unborn young are nourished by egg yolk. There are two types of viviparity in fish. In histotrophic viviparity, the zygotes develop in the female's oviducts, but she provides no direct nutrition; the embryos survive by eating her eggs or their unborn siblings. In hemotrophic viviparity, the zygotes are retained within the female and are provided with nutrients by her, often through some form of placenta.
Poeciliinae is a subfamily of killifish from the family Poeciliidae which contains species from the Americas which are collectively known as the livebearers because many, but not all, of the species within the subfamily are ovoviviparous.
Ranoidea is a genus of frogs in the subfamily Pelodryadinae. They are found in Australia, New Guinea, and two nearby groups of islands: the Maluku Islands, and the Louisiade Archipelago. The circumscription of this taxon is still controversial.
