Viviparous Poisson

The term of " vivipares"

The characteristic of the viviparous Poisson S compared to the oviparous animals, is that the Alevin S are born already formed. These fish thus do not lay a eggs. It is in fact righter to speak about ovoviviparity. Indeed, if the viviparous Embryon is nourished in the center of his/her mother, the ovoviviparous embryo is nourished in the egg, which hatches a little before the birth. However, in the language running, one speaks about viviparous, for practical reasons. When you see the word viviparous, it will thus act almost always the ovoviviparous ones, i.e. of poecilidés (ex: guppys, platys, mollys, sword-tails…). The true viviparous ones are goodeidés (ex: Ameca splendens).

Characteristics and maintenance

The viviparous ones appeared very late, after the oviparous animals, has L `Oligocène (44-38.5 million years) and with the Miocène (28.5 million years). This evolution, if L `one believes of it the theory of Darwin is a means of protecting the young people from predatory while making them mobile as of the birth, which explains why only 6 has 150 alevins per range make it possible the species to proliferate. The first viviparous ones were discovered by the Ichtyologiste S in the middle of the 19th century, and were imported at the beginning of the 20th century.

Poecilidés characteristics similar have to the family of the cyprinodontidae. This family is originating in America, of a zone going of the south of the United States, in the south of the Amazonian Bassin. Most popular of these fish is the Guppy (poecilia reticulata), for which contests are even organized. The first specimen was discovered in 1859. The wild form was coloured little, since the species available in the trade are for totality exits of breeding, and of selection, often of Asian origin. The most widespread species in the trade are the guppy, the Platy, the carry-sword, and the molly. These fish being often hybrids of 2 species it would be inaccurate to use their scientific name. It is necessary to have 2 to 3 females per male, because those spend their time pursueing them. It is often recommended to maintain them in a relatively hard and alkaline water, but in a wild state they live in very diverse water on the physicochemical level. The fish living in earthy waters live in zones which are not crossed by the wet forest, contrary with much of American fish. It is in fact only the specimens of breeding which are accustomed to hard regional water, and which has evil to be rehabilitated has fresh water. The majority of viviparous are liked in water enters 23 and 26 degrees, with a hardness located between 5 and 20 dGh. These poisons can make at the adulthood from 2 to 20 cm following the species. A slightly brackish water (presence of salt) is recommended only to look after the diseases and is not to in no case necessary in maintenance the viviparous ones, whatever it are (and this contrary to much of generally accepted ideas…).

The majority of viviparous are Omnivore S.A. tendency vegetarian, for this reason they must be nourished little and often (they have small a Estomac and are quickly gavés). The carnivorous will be nourished alive preys like small Crustacé S. The viviparous ones are too often regarded as " red water chaude" fish; (moreover, at the platys one observes that the specimen more required is the red platy or platy coral), little originals and offering little interest. But it is not unfortunately or more of fish for beginners. The intensive Asian breeding of these last years makes that the majority of the species coming from the trade (especially guppys) unfortunately became far from resistant. To benefit fully from these fish it is thus recommended to get them in clubs, at private individuals or near a specialized association (like the AFV). You will then have fish of good quality, which it are wild or hybrid. Their resistance, their excellent sociability and their facility of reproduction will enchant you then.

To recreate a Biotope resembling the centraméricain medium, while observing the particular conditions of maintenance out of aquarium, you can use a well planted vat (if possible of plants originating in the medium like the majority in the cabombas and echinodorus). Many plants of surface are advised besides for the needs for fish. You will have an idea of the number of plants total necessary while making: surface aquarium in cm (L X L) divided by 50. The decoration will be composed of plants exclusively, or also of rocks and roots. The ground can be made up of gravel of different granulometry (for example stream sand or gravel). In summer, it is possible to maintain them in a basin of shone upon garden, they will reach a big size then. For the maintenance of fragile species, a naked vat can be preferred, because easier to clean.

It should be noted that WHO makes use of guppys and gambusies in the tropical countries to get rid of the larvae of mosquito (vectors of paludism) of which they are fond of delicacies. They are sometimes even introduced into tanks D `drinking water. That explains why one finds nowadays poecilidés in many areas of planet.

In the event of health issue, best is to make a good water change, and if required to add salt of aquarium in water (5g/L). Attention because the plants and will corydoras them support salt badly.

Reproduction

The reproduction is very easy, but to keep a beautiful stock is much harder. The male is distinguished from the female by a gonopode (or a andropode which very early appears at goodéidés) in the place of the anal fin. This body allows the coupling. As for the female, it is often larger than its partner and less coloured. Attention, because sometimes, in the sword-tails in particular, it arrives that the " femelles" are in fact of the late males, and thus which they reveal their male character only after approximately a year.

The coupling is very short, and can give place to several births in approximately a month of interval, thanks to the characteristic of the ovoviviparous female to store sperm (contrary to the goodeidae). A dark task appears behind the belly of the female, which generally becomes black (even reddish at certain species) with the wire of gestation. One can see the eyes of future alevins a few days before the low setting. On average, 30 alevins are born each time, according to the ranges (up to 100 between the 3 èmes and 6èmes carried). The alevins are born the tail the first and move towards the source of light, it is thus recommended to have floating plants. One can protect them from the appetite of their elder by isolating alevins in a small vat, and by nourishing them of artémias. After one month, the eyes, the heart, the blister and stops it principal are formed perfectly. After 2 months they are not likely theoretically any more to be made devour. Maturity intervenes around 3 months, but it is advised to wait 6 months to make them couple itself. They will grow more quickly at a temperature of at least 26°C, and if they are nourished thanks to a varied food, alive inter alia, several times in minor amount (nauplies of artémias, flakes crushed etc…). For a maximum growth, it is recommended to make frequent water changes. it is inaccurate to say that the viviparous ones are prolific fish since they can put low only one about thirty alevins per month (whereas cichlidés can lay several hundreds of eggs every week for example), on the other hand the alevins are much more débrouillards, and manage to better survive without " aide" external. The term of viviparous is one cannot generic, and it is often difficult to be found there. the point on the principal known families.

The family of Poeciliides

Most known and the most spread, it contains the kinds: Alfaro (of Guatemala in Panama) Belonesox (southern of Mexico and Honduras) Brachyrhaphis (south-western of Mexico, Costa Rica, Panama) Gambusia (Atlantic Slope of the Central America and the Caribbean) Girardinus (Cuba and Costa Rica) Heterandria (Caroline and Florida) Phallichthys (of Guatemala in Panama) Phalloceros (Center of Brazil, Paraguay, Argentina, Uruguay) Poecilia (of the south of the USA in the French Guiana) Priapella (waters running of Mexico) Quintana (Cuba) Xiphophorus (Mexico, Honduras)

The family of Goodeidae

Second the most spread family, it gathers forty species in ten kinds: Ameca, Characodon, Goodea, Ilyodon, Skiffia, Xenotoca, Zoogoneticus. Present in the highlands of Mexico they are characterized by the fact that the body of the male is transformed into andropode. Measuring between 4 and 10 cm on average, they are what one calls viviparous truths and are unfortunately very often in the process of disappearance.

The family of Jenynsiides

Originating in the south of Brazil and Uruguay, it contains the species Jenynsia lineata. The females can measure up to 13 cm while the males reach only 4 of them. They have the characteristic to have the sexual organ directional.

The family of Anablepidae

She contains the Anableps kind, originating in Mexico. Brackish Poisson of about thirty cm, one call them " four yeux" since each eye is divided into two, the upper part allowing to see out of water while the lower part allows to see under water.

The family of Hemirhamphides

" half-becs" are originating in tropical Asia and contain the kinds Dermogenys, Hemirhamphodon and Nomorhamphus. They are fish of surface being able to exceed the 10 centimetres.

The protection of the viviparous savages

Among the various " families; vivipares" , one of it, that of the goodeidae, are particularly threatened. Indeed these fish are endemic of one of the most polluted countries world: Mexico. Their natural environment tends to be reduced more and more, and as these fish are very sensitive to pollution the existing populations also decrease in a dramatic way.

Some aquarists, under the aegis of the " Fish Ark" and of the AFV in France, thus chose to devote one or more vats to species threatened of goodeidae, with an aim of maintaining them long-term and of thus avoiding their total extinction. In the long term the goal is to reintroduce these species in their natural environment, when this one is again made livable.

Some sites vivipariophiles

Association Viviparous France
Passion Viviparous
the Scientific Workshop
Denis Web
Guppy Welcome France
at viviparous the

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