Guppy

Guppy
Male (left) and female (right) guppies
Conservation status
Secure
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Cyprinodontiformes Family: Poeciliidae Genus: Poecilia Species: P. reticulata
Binomial name
Poecilia reticulata Peters, 1859
Synonyms
Acanthocephalus guppii A. reticulatus Girardinus guppii G. petersi G. poeciloides G. reticulatus Haridichthys reticulatus Heterandria guppyi Lebistes poecilioides L. reticulatus Poecilia poeciloides Poecilioides reticulatus

Guppy is the common name for the various small, freshwater, live-bearing fish in the species Poecilia reticulata of the Poecilidae family of the order Cyprinodontiformes. Also known as the millionsfish (Agbayani 2007), the guppy is one of the most popular freshwater aquarium fish species in the world as well as a popular experimental fish.

Overview and description

The guppy, Poecilia reticulata, is a member of the subfamily Poeciliinae (livebearers) in the cyprinodontiform family Poeciliidae. Poeciliidae (poeciliids) are freshwater and brackish fish found in the New World (from North America to South America) and in Africa (including Madagascar) (Nelson 1994). Members of Poeciliidae are characterized by having pectoral fins placed high on the side of the body as a result of the radials placed in a dorsal position on the scapulocoracoid (Nelson 1994). They also are characterized by anterior placement of the pelvic fins and pleural ribs on the first several haemal arches (Nelson 1994). As cyprinodontiformes (Order Cyprinodontiformes), they have a symmetrical caudal fin, supported internally by one epural, and generally marked sexual dimorphism with the males often brightly colored (Nelson 1994).

The subfamily Poeciliinae, to which guppies belong, are characterized by livebearing (except Tomeurus), with the males having elongated anterior anal fin rays (gonopodium) with internal fertilization and females producing eggs with large yolks (Nelson 1994). Members of this subfamily are found from the Eastern United States south to Argentina and Uruguay (Nelson 1994). In addition to guppies, other popular aquarium fish belonging to this subfamily include the mosquitofishes (Gambusia affinis and Gambusia holbrooki), the mollies (also in genus Poecilia, such as the sailfin molly, Poecilia latipinna), and the swordtail and platies of the genus Xiphophorus.

The genus Poecilia to which the guppy belongs, is one of about 22 genera in the subfamily Poecillnae. Nelson (1994) recognizes 49 species in the genus, but others separate the many species of limias into their own genus, Limia.

The guppy, Poecilia reticulata is a small member of the Poecilidae family, with females typically 4-6 centimeters long and males about 2½–3½ centimeters long. Like all other members of the family except the genus Tomeurus (which is egg-laying), the guppy is live-bearing.

Taxonomy

Robert John Lechmere Guppy discovered this tiny fish in Trinidad in 1866, and the fish was named Girardinus guppii in his honour by Albert C. L. G. Gunther later that year. However, the fish had previously been described by Wilhelm Peters in 1859 on material collected from South America. Although Girardinus guppii is now considered a junior synonym of Poecilia reticulata, the common name "guppy" still remains. Over time guppies have been given a variety of taxonomic names, although Poecilia reticulata is the name currently considered to be valid.

Distribution

Guppies are native to Trinidad and parts of South America, specifically Antigua and Barbuda, Barbados, Brazil, Guyana, Netherlands Antilles, Trinidad and Tobago, the US Virgin Islands, and Venezuela.

However, guppies have been introduced to many different countries on all continents, except Antarctica. Sometimes this has occurred accidentally, but most often as a means of mosquito control, the hope being that the guppies would eat the mosquito larvae slowing down the spread of malaria. In many cases, these guppies have had a negative impact on native fish faunas.

Ecology and behaviour

There is a great deal of variety between the populations, many with distinctive coloring or patterning. Those that live in habitats where predators are common tend to be less vividly decorated as a protective measure. Populations that deal with fewer predators are much more colorful. Recent studies suggest that vividly colored males are favored via sexual selection (Handicap principle) while natural selection via predation favors subdued tones. As a result, the dominant phenotypes observed within a reproductively isolated community are a function of the relative importance each factor has in a particular environment.

Occasionally male guppies may behave aggressively towards each other, engaging in fin-nipping and other bullying behaviour. Guppies live in complex social networks, choosing social partners and remembering them. .

Guppies are a seminal species for evolutionary biologists because predation often varies over small geographic areas. Both historical work and recent studies are summarised in Anne Magurran's Evolutionary Ecology: the Trinidadian Guppy.

Reproduction

Guppy fry in an aquarium, 1 week

Guppies are highly prolific livebearers. The gestation period of a guppy is 22-30 days, with an average of 28 days. After the female guppy is inseminated, a dark area near the anus, known as the gravid spot, will enlarge and darken. Guppies prefer water temperatures of about 28 °C (82 °F) for reproduction. The female guppy has drops of between 2-200 fry, typically ranging between 30 and 60. After giving birth, the female is ready for conception again within only a few hours.

In the aquarium

Guppy standards

The guppy prefers a hard water aquarium and can withstand levels of salinity up to 150% that of normal sea water., which has led to them being occasionally included in marine tropical community tanks, as well as in freshwater tropical tanks. Guppies are generally peaceful, though nipping behaviour is sometimes exhibited between male guppies or towards other top swimmers like platys and swordtails and occasionally other fish with prominent fins such as angelfish. Its most famous characteristic is its propensity for breeding, and it can breed in both fresh water and marine aquariums.

Guppy breeding by aquarists produces variations in appearance ranging from color consistency to fantails and "spike" swordtails. Selective breeding has created an avid "fancy guppy" collector group, while the "wild" guppy maintains its popularity as one of the hardiest aquarium fish.

Experienced aquarists breeding their own guppies are aware that the adults will eat their young and, therefore, provide safe zones for the fry. Specially designed livebearer birthing tanks, which can be suspended inside the aquarium, are available from aquatic retailers. These serve the dual purpose of shielding the pregnant female from further attention from the males, and of providing a separate area for the newborn young as protection from being eaten by their mother. Although if a female is put in the breeder box too early or late it will cause her to have a miscarriage.

See also

• Poecilia wingei, the Endler guppy
• Micropoecilia picta, the swamp guppy

External links

• Poecilia reticulata (TSN 165903). Integrated Taxonomic Information System. Accessed on June 8 2004.
• Template:FishBase species

References

ISBN links support NWE through referral fees

Nelson

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

• Guppy  ^history

The history of this article since it was imported to New World Encyclopedia:

• History of "Guppy"

Note: Some restrictions may apply to use of individual images which are separately licensed.