The guppy (Poecilia reticulata), also known as millionfish and rainbow fish, is one of the world’s most widely distributed tropical fish, and one of the most popular freshwater aquarium fish species. It is a member of the family Poeciliidae and, like almost all American members of the family, is live-bearing.Guppies, whose natural range is in northeast South America, were introduced to many habitats and are now found all over the world. They are highly adaptable and thrive in many different environmental and ecological conditions.Male guppies, which are smaller than females, have ornamental caudal and dorsal fins, while females are duller in color. Wild guppies generally feed on a variety of food sources, including benthic algae and aquatic insect larvae. Guppies are used as a model organism in the fields of ecology, evolution, and behavioral studies
Guppies were first described in Venezuela as Poecilia reticulata by Wilhelm Peters in 1859 and as Lebistes poeciliids in Barbados by De Filippi in 1861. It was named Girardinus guppiiby Albert Günther in honor of Robert John Lechmere Guppy, who sent specimens of the species from Trinidad to the Natural History Museum in London. It was reclassified as Lebistes reticulatus by Regan in 1913. Then in 1963, Rosen and Bailey brought it back to its original name, Poecilia reticulata. While the taxonomy of the species was frequently changed and resulted in many synonyms, “guppy” remains the common name even as Girardinus guppy is now considered a junior synonym of Poecilia reticulata.
applies exhibit sexual dimorphism. While wild-type females are grey in body color, males have splashes, spots, or stripes that can be any of a wide variety of colors.The size of guppies vary, but males are typically 1.5–3.5 cm (0.6–1.4 in) long, while females are 3–6 cm (1.2–2.4 in) long.
A variety of guppy strains are produced by breeders through selective breeding, characterized by different colors, patterns, shapes, and sizes of fins, such as snakeskin and grass varieties. Many domestic strains have morphological traits that are very distinct from the wild-type antecedents. Males and females of many domestic strains usually have larger body size and are much more lavishly ornamented than their wild-type antecedents.
Guppies have 23 pairs of chromosomes, including one pair of sex chromosomes, the same number as humans.The genes responsible for male guppies’ ornamentations are Y-chromosome linked and are heritable
Birth of guppy fry
Guppies are highly prolific livebearers The gestation period of a guppy is typically 21–30 days, varying considerably. Reproduction typically continues through the year, and the female becomes ready for conception again quickly after parturition. Male guppies, like other members of the Poeciliidae family, possess a modified tubular anal fin called the gonopodium, located directly behind the ventral fin. The gonopodium has a channel-like structure through which bundles of spermatozoa, called spermatozeugmata, are transferred to females. In courted mating, where the female shows receptive behavior following the male’s courtship display, the male briefly inserts the gonopodium into the female’s genital pore for internal fertilization. However, in the case of sneaky mating where copulation is forced, the male approaches the female and thrusts the gonopodium at the female’s urogenital.
Once inseminated, female guppies can store sperm in their ovaries and conducts, which can continue to fertilize ova up to eight months.Because of the sperm-storage mechanism, males are capable of posthumous reproduction, meaning the female mate can give birth to the male’s offspring long after the male’s death, which contributes significantly to the reproductive dynamics of the wild guppy populations.
The guppy has been successfully hybridized with various species of molly (Poecilia latipinna or P. velifera), e.g., male guppy and female molly. However, the hybrids are always male and appear to be infertile. The guppy has also been hybridized with the Endler’s livebearer (Poecilia wingei) to produce fertile offspring, with the suggestion that, despite physical and behavioral differences, Endler’s may represent a subspecies of Poecilia reticulata rather than a distinct species