Fruchtbarkeit

Guppy Weibchen haben nur eine begrenzte Anzahl Follikel in ihren Ovarien, die zu Eiern heranreifen können. Das beeinhaltet, dass die "Fruchtbarkeit" (Produktion befruchteter Eier)des Weibchens nach Stamm und Alter unterschiedlich sein kann. Die größte Fruchtbarkeit liegt zwischen dem 3. bis 6. Monat. Die Fruchtbarkeit hängt auch von den Verpaarungsmethoden des Züchters ab. Hält man die Weibchen in sauberen Becken und füttert man sie großzügig mit hoch proteinhaltigem Futter, kann dieses einen großen Einfluß auf ihre Fruchtbarkeit besitzen.

Laut Dr. David Reznick, dem Guppy Wissenschaftler, können die Weibchen bis zu 20 Würfe haben, dann bekommen sie eine Meopause und leben dann weiter ohne Junge zu gebären.

Die weibliche Nachkommensproduktion folgt einer Glockenkurve. Werden sie mit Männchen zusammen gehalten, beginnt die Produktion frühestens mit 21/2 Monaten in Form von kleinen Würfen bis zu 20 Jungen. Im Alter von 6 - 8 Monaten erhält die Produktion ihr Maximum mit 50 - 100 Jungen. Je größer das Weibchen ist, desto mehr Junge bringt sie hervor. Guppyzucht ist ein Zahlenspiel, daher nehmen die Züchter nur 2 Würfe von einem Weibchen, da das Beste, was sie zu bieten hat, in diesen beiden Würfen enthalten sein wird. Wieviel Junge man genau von einem Weibchen nehmen soll, hängt von dem Prozentsath der gewünschten Merkmale ab. Die meisten Züchter nehmen die Weibchen im Alter von neun Monaten aus der Zucht. Nochmals, die genauen Zahlen sind stammesabhängig. Nach neun Monaten verringert sich die Eiproduktion, oft bis zu einem Punkt, an dem nur noch einige unbefruchtete Eier produziert werden.

Die Tragezeit des Guppys beträgt ungefähr 25 Tage, aber sie kann von 21 bis 30 Tage dauern, und bei seltenen Gelegenheiten bis zu 40 Tagen. Wenn du ein relativ unfruchtbares Weibchen besitzt, das nicht viele Junge hervorbringt, solltest du mit deinen Schutzvorrichtungen ab dem 20. Tag beginnen.



Englische Version
Female guppies have only a certain number of follicles in their ovaries capable of maturing into eggs. This means that the female "fertility" (fertilized egg production) can vary according to strain and age. The peak of fertility can range between 3 to 6 months. It is also related to the breeder's husbandry methods. Keeping females in clean tanks and feeding them generous amounts of high protein food can have a huge effect on their fertility.

According to Dr. David Reznick, the guppy scientist, females have up to 20 drops and then go through menopause, and can live the rest of their lives without bearing young.

Female fry production follows a bell curve. Raised alongside males, production begins as early as 2 1/2 months of age with small drops of 10 to 20. By 6-8 months age, drops peak in size between 50-100 fry. The larger the female, the more fry she produces. Guppy breeding is a numbers game, so breeders usually take only two drops from a female, since the best she has to offer genetically will be included in those two drops. Exactly how many fry you should take from a female before retiring her depends on the percentage of her offspring expressing the desirable traits. Most breeders retire females at the age of nine months. Again, the actual numbers are strain specific. After nine months, egg production declines, often to the point where only a few unfertilized eggs are produced.

The gestation period for the guppy is about 25 days, but it can range from 21 to 30 days, and on rare occassions up to 40 days. If you have an relatively infertile female who does not produce a lot of young, you should begin providing cover for young after 20 days.


No problem with fertility with this female guppy[bearbeiten]Factors Affecting Female Fertility
If your female does not seem to be producing young, the standard caveat is: "Is she or her tank mates eating them as fast as they are born?" If you are satisfied that the female is not eating her young, then consider the following factors:

Infertile strain. You may have a strain that is low in fertility. This is often the result of inbreeding for three generations or more. Try one of the crosses outlined in the topic "Designing a Breeding Program" (line cross or out cross) to improve your strain's fertility.
Hybrid infertility. Sometimes a cross between two unrelated strains produces infertile offspring. This is rare.
Male infertility. You may have matched her with an infertile male, or a male with a low sperm count. Choose healthy, active males that show a lot of interest in the female.

Female infertility. You may have chosen an infertile female. Either genetic or environmental conditions may result in underdeveloped ovaries.
Poor feeding regime. Females require good quality food in quantity. High protein and fatty foods (such as worms) promote egg production.

Poor female health. You may have low oxygen levels in the water, or it may be high in nitrates and ammonia. Overcrowding reduces oxygen levels, triggering a shut down of egg production. Sick females often become infertile, sometimes permanently. Females kept in optimum conditions have larger spawns.
Poor light levels. Females require as a minimum, a reading level of light. Brighter lights will often have a marked effect on female fertility and egg production.
Keeping females in well-maintained tanks and feeding them live or frozen foods are the best remedies for non-producing females. Frozen bloodworms are a particularly good food for inducing fertility. However there is a risk of disease with bloodworms.