Nimble and brightly colored, the Guppy have been used in aquariums since the early 1900´s. However, their use is not limited to this. Due to their voracious habit of eating insect larvae, in Eastern countries the Guppy are used as instruments of biological control. During the 30´s, they were also used in Brazil to fight Malaria and Yellow Fever transmitters. They are also utilized in laboratories for eco-toxicological, genetic, behaviorist and reproductive experiments.

Origin:
The Guppy are native to South and Central Americas. They are mainly found in estuaries located in Barbados, Trinidad Tobago, Venezuela, in the Guiana and in northern Brazil. Also known as Rainbow Fish, Barrigudinho (potbellied), Bandeirinha, (little flag), Sarapintado (iridescent|) and Guppy, they can be found worldwide. Before being scientifically classified as Poecilia reticulata, the Guppy were known as Girardinus guppyi and Lebistes reticulatus. In fact, they were named after Robert J.L Guppy, who was honored by the English naturalist Guenther who, in 1860, received from Robert the first fish collected in Central America. They belong to the family Poeciliidae that also comprises the Mollies, Swordtails and the Platies.
They are easy to care and do well in all aquarium sizes, since the required water pH and temperature are observed. It is interesting to have more females in one aquarium. A 3 to 1 ratio is the ideal one.

Reproduction:
The females do not lay eggs; they give birth to ready fries. Thus, they are classified as ovoviviparous fishes. Many times they are incorrectly considered as viviparous fishes, but there is a great difference between these two kinds of reproduction. The word viviparous refers to embryos directly nourished by the mother via a structure, which is similar to the umbilical cord. This happens, for instance, with some shark species. The word ovoviviparous refers to embryos nourished via vitelline sac, enclosed by a membrane (egg) and that develop within the mother’s body. In general, one could say that they “hatch" eggs in their inside. The fries are safely developed within these eggs in the interior of the mother. When they are ready, the shell breaks and the fries are expelled by the mother.

The males are distinguishable from the females due to their bigger tail, their lively colors and to the presence of the gonophore, a structure similar to a small pipe located on the ventral side. This structure allows transferring the masculine gametes into the female body, and the consequent fertilization. The females have a spot on the ventral side, next to the tail, that becomes darker when the eggs start to grow. When the younglings are ready to be born, this spot becomes "lower", and the female gets paunchy and short of breath.

For breeding, it is advisable to have between 3 and 5 females per male. This species, similarly to other ovoviviparous fish, does not care for the younglings after their birth. Moreover, the permanence of the small fries with the adult fishes, even with their mothers, can be harmful, as the latter tend to swallow them. Thus, the pregnant females shall be placed in individual aquariums where, as soon as the younglings are born, they may be separated from their mothers. It is recommended a 15-20-liter aquarium with natural plants as Elodeas, Cabombas, Sagittarias and aquatic Ferns, so that the fries may refuge themselves. The pregnancy period is short, around 20, 30 days. The younglings must be fed with alcon Alevinos during the first month.

When they complete two months it is possible to distinguish the males from the females, and they are ready to reproduce. In this phase, they may be fed with other animal food rations as alcon Guppy, alcon Basic and alcon Gold Spirulina Flakes. For a good development, it is recommended to allow them to reproduce only when they get four months.One interesting feature of these fishes is the capacity the females have of storing the male sperm for a long period, being able to have 3 successive pregnancies without requiring the male presence for a new fecundation. This characteristic is very important when one intends to perform specific crossings between previously chosen males and females. In order to achieve the desired crossing results, it is necessary to “clean” the female, that is, to prevent it to keep contact with males during a 6-month period, so that it may bring to an end the sperm from other males.

For a successful reproduction, good environmental conditions shall be observed as, for instance, a temperature around 28 ºC and a pH around 7.2.
With proper care and a little of daily attention, the Guppy, definitely, will make your aquarium more vivid and colorful.