Kingdom:
Animalia
Phylum:
Chordata
Class:
Actinopterygii
Order:
Cyprinodontiformes
Family:
Poeciliidae
Genus:
Poecilia
Species:
P.reticulata
Taxonomy :
It was named Girardinus guppii by Albert Günther in honor of Robert John Lechmere Guppy, who sent specimens of the species from Trinidad to the Natural History Museum in London.[7] It was reclassified as Lebistes reticulatus by Regan in 1913. Guppies were first described in Venezuela as Poecilia reticulata by Wilhelm Peters in 1859 and as Lebistes poecilioides in Barbados by De Filippi in 1861. While the taxonomy of the species was frequently changed and resulted in many synonyms, "guppy" remains the common name even as Girardinus guppii is now considered a junior synonym of Poecilia reticulata.[5]. Then in 1963, Rosen and Bailey brought it back to its original name, Poecilia reticulata.
Distribution and habitat :
The guppies were expected to eat the mosquito larvae and help slow the spread of malaria, but in many cases, these guppies have had a negative impact on native fish populations.[10] Field studies reveal that guppies have colonized almost every freshwater body accessible to them in their natural ranges, especially in the streams located near the coastal fringes of mainland South America. Sometimes this has occurred accidentally, but most often as a means of mosquito control. Guppies are native to Antigua and Barbuda, Barbados, Suriname, Guyana, Trinidad and Tobago, and Venezuela.[8][9] However, guppies have been introduced to many different countries on every continent except Antarctica. Although not typically found there, guppies also have tolerance to brackish water and have colonized some brackish environments.[5] They tend to be more abundant in smaller streams and pools than in large, deep, or fast-flowing rivers.[11] They also are capable of being acclimated to full saltwater as well as being used to cycle saltwater aquariums like their molly cousins.
Breeding of Guppies ;
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.[12] 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 colours, patterns, shapes, and sizes of fins, such as snakeskin and grass varieties. Males and females of many domestic strains usually have larger body size and are much more lavishly ornamented than their wild-type antecedents.[13]
Guppies have 23 pairs of chromosomes, including one pair of sex chromosomes, the same number as humans.[14] The genes responsible for male guppies' ornamentations are Y-chromosome linked and are heritable.[15]. Guppies exhibit sexual dimorphism. Many domestic strains have morphological traits that are very distinct from the wild-type antecedents.
Life cycle :
Male guppies mature in 7 weeks or less.[5] Total lifespan of guppies in the wild varies greatly, but it is typically around 2 years.[16] Variations in such life historic characteristics of guppies are observed in different populations, indicating that different evolutionary pressures exist. Guppies are well developed and capable of independent existence without further parental care by the time they are born. Brood size is extremely variable, yet some consistent differences exist among populations depending on the predation level and other factors.[5] Females of matching body sizes tend to produce more numerous but smaller-sized offspring in high-predation conditions. Female guppies first produce offspring at 10–20 weeks of age, and they continue to reproduce until 20–34 months of age. Young guppies school together and perform antipredator tactics. Two generations of guppies per year occur in the wild.
Maturity :
Female guppies' reproductive success is also related to age. Male and female guppies from high-predation regions mature faster and start reproducing earlier, and they devote more resources to reproduction than those from low-predation regions.[17] Females from high-predation regions reproduce more frequently and produce more offspring per litter, indicating that they are more fecund than low-predation females. Older females produce offspring with reduced size and at increased interbrood intervals.[18]. Guppies' body sizes are positively correlated with age, and their size at maturation varies highly depending on the predation risk of the occupied environments.
Senescence :
Female guppies from high-predation environments experience a significant increase in mortality at 6 months of age, while those from low-predation environments do not suffer increased mortality until 16 months. No significant difference is seen in postreproductive lifespans. Guppies from high-predation environments suffer high extrinsic mortality rate because they are more likely to be killed by predators. However, guppies from high-predation environments were found to have longer lifespans because their reproductive lifespans are longer. Senescence
One major factor that affects wild guppies' senescence patterns is the mortality rate caused by predation.
Population regulations ;
In addition to senescence pattern, resource availability and density also matter in regulation of guppy populations. When food is abundant, they increase brood size.[19] Differential reproductive allocation can be the cause of seasonality of life-history characteristics in some guppy populations. Guppies reduce their fecundity and reproductive allocation in response to scarce food. For example, during the wet season from May to December, guppies in the Northern Range of Trinidad reduce their investment in reproduction regardless of predation level, possibly in response to decreased food resources.[20] Population density also matters in simpler environments because higher intraspecific competition causes a decrease in reproductive rate and somatic growth rate, and a corresponding increase in juvenile mortality rate due to cannibalism.[21] It was confirmed that in low-predation environments, guppy populations are in part regulated by density.[22].
Reproduction :
Guppies are highly prolific livebearers.[47] The gestation period of guppies varies considerably, ranging from 20 to 60 days at 25 to 27 C and depending on several environmental factors.[48][49] Reproduction typically continues through the year, and the female becomes ready for conception again quickly after parturition.[5] Male guppies, like other members of the family Poeciliidae, possess a modified tubular anal fin called the gonopodium, located directly behind the ventral fin. 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 pore.[50]
Once inseminated, female guppies can store sperm in their ovaries and gonoducts, which can continue to fertilize ova up to eight months.[51] 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.[52]
The guppy has been successfully hybridised with various species of molly (Poecilia latipinna or P. 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. The gonopodium has a channel-like structure through which bundles of spermatozoa, called spermatozeugmata, are transferred to females. However, the hybrids are always male and appear to be infertile.[53] The guppy has also been hybridised with the Endler's livebearer (Poecilia wingei) to produce fertile offspring, with the suggestion that, despite physical and behavioural differences, Endler's may represent a subspecies of Poecilia reticulata rather than a distinct species. velifera), e.g., male guppy and female molly.
Inbreeding depression ;
Due to the extensive selective breeding of guppies for desirable traits such as greater size and colour, some strains of the fish have become less hardy than their wild counterparts. Immense inbreeding of guppies has been found to affect body size, fertility and susceptibility to diseases.[56].
In the aquarium :
Large strains:
A - Veil tail
B - Triangle tail
C - Fan tail
D - Flag tail
Sword strains:
E - Double sword
F - Upper sword
G - Lower sword
H - Lyre tail
Short strains:
I - Spade tail
J - Spear tail
K - Round tail
L - Pin tail
Guppies prefer a hard-water aquarium with a temperature between 25.5 and 27.8 °C (78 and 82 °F) and salt levels equivalent to one tablespoon per 19 L (5 US gal).[57] They can withstand levels of salinity up to 150% that of normal seawater,[58] 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 members of the genus Xiphophorus (platies and swordtails), and occasionally other fish with prominent fins, such as angelfish. The female guppy has drops of two to 200 fry at a time, typically ranging between 30 and 60.[62]
Well-fed adults do not often eat their own young, although sometimes safe zones are required for the fry. Pregnant female guppies have enlarged and darkened gravid spots near their anal vents. Specially designed livebearer birthing tanks, which can be suspended inside the aquarium, are available from aquatic retailers. Feeding fry live foods, such as baby brine shrimp, microworms, infusoria and vinegar eels, is recommended. Just before birth, the eyes of fry may be seen through the translucent skin in this area of the female's body.[61] When birth occurs, individual offspring are dropped in sequence, typically over a period of one to six hours. Guppies should not be kept as a single fish in an aquarium because both males and females show signs of shoaling, and are usually found in large groups in the wild.[59] Its most famous characteristic is its propensity for breeding, and it can breed in both freshwater and marine aquaria.[60]
Guppies prefer water temperatures around 22.2–26.1 °C (72–79 °F) for reproduction. These also serve to shield the pregnant female from further attention from the males, which is important because the males sometimes attack the females while they are giving birth.[63] It also provides a separate area for the newborn young as protection from being eaten by their mother.[64] However, if a female is put in the breeder box too early, it may cause her to have a miscarriage. Guppy grass, water sprite, water wisteria, duckweed, and java moss are all good choices. A continuous supply of live food, such as Daphnia or brine shrimp, keep adult fish full and may spare the fry when they are born.[65] Young fry take roughly three or four months to reach maturity. Well-planted tanks that offer barriers to adult guppies shelter the young quite well. Alternatives include finely ground flake food, egg yolk, and liquid fish food, though the particulates in these may be too large for the youngest fry to eat.[66].
 ){kind=link}
0 Comments