Guppy
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? Guppy Conservation status:
Secure
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| Poecilia
reticulata Peters, 1859 |
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The guppy, alternatively guppie (Poecilia reticulata) is one of the most popular freshwater aquarium fish species in the world. It is a small member of the Poecilidae family (females 3 centimetres long, males 2 centimetres long) and like all other members of the family, is live-bearing. It prefers a hard water aquarium and can withstand a surprising degree of salinity. Its most famous characteristic is its propensity for breeding.
The female guppy is drab brown to grey in colour. The much smaller male naturally has a colourful caudal fin (tailfin), showing wide variety in the wild, depending on where the stock comes from. These colourful variations have been considerably enhanced in shape and colour by selective breeding.
In its natural environment in Central and South America, guppies are often found as isolated breeding populations. 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. Populations that deal with less predators are much more colorful. Recent studies suggest that vividly colored males are favored via sexual selection while natural selection via predation favors subdued tones. As a result, the dominant phenotypes observed within a reproductively isolated community is a function of the relative importance each factor has in a particular environment.
Robert John Lechmere Guppy (1836-1916) discovered this tiny fish in Trinidad in 1866, although the fish was known to German aquarists prior to that time. The guppy escaped from captivity and lives in a feral condition in much of the warmer regions of the world. It has been introduced to some areas to keep down the mosquito population and help fight malaria, usually with mixed or negative results to the local ecosystem. The guppy can be found in its native habitat in small streams and ponds of virtually any size. In Trinidad they are commonly known as "millions" for obvious reasons.
Guppy breeding by aquarists produces variations in appearance ranging from colour 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. The gestation period of a guppy is 22-26 days. When the female guppy becomes fertilized, a dark area near the anus, known as the gravid spot, will enlarge and darken . This area is like a window into the guppy, and it is actually the eyes of the unborn fry when near birth. Guppies prefer water temperatures of about 72 degrees F for reproduction. After giving birth, the female is ready for conception within a few hours. If a male does not mate with the female soon after birth, the female can use stored sperm from the previous mating. For people breeding their own guppies, be aware that the adults will eat their young if they are hungry.
This fish has been introduced to the Netherlands where it lives in the cooling water of the Corus Steelmill near IJmuiden. The result has been extraodinary; the fish thrive and have increased in size. Fish of 12 cm are the norm.
Over time, many species are assigned a different taxonomic name. The guppy is no exception:
- Lebistes reticulatus
- Acanthocephalus guppii
- A. reticulatus
- Girardinus guppii
- G. petersi
- G. poeciloides
- G. reticulatus
- Haridichthys reticulatus
- Heterandria guppyi
- Lebistes poecilioides
- Poecilia poeciloides
- Poecilioides reticulatus.
- For now: Poecilia reticulata