20.5.12
Breeding
The Guppy is probably the easiest fish of all to breed. In fact the only way of being sure that you will not get baby Guppies is to get only male Guppies. Many people do this. The Males are the more colourful. Getting only female Guppies is not a reliable way of preventing reproduction because the Females could have mated before you got them. Unlike with most fish, fertilization in Guppies is internal. This also applies to their near relatives, the Mollies, Platies and Swordtails.
A female Guppy can have more than one lot of babies from one mating, so the mating could have happened a considerable time before birth. The gestation period of Guppies averages about 28 days. This varies with external factors. The water temperature may have an effect. Higher temperatures may shorten the gestation period, and day length also seems to be important, with a longer day length shortening the gestation.
A female Guppy can often become pregnant at as young as two months, having her first babies at three months old. She can the continue having babies every 28 days or so for the rest of her life. The Guppy produces fewer babies in each litter than most fish, but the babies are bigger in relation to the fish's adult size than most fish babies. This tends to give a high survival rate. This coupled with the short generation time means that Guppies can multiply quickly. In some places there are so many Guppies visible in the water that they have been called the 'Millions fish'.
Most strains of Guppy eat their own babies, as well as the babies of other fish. Most types of other fish will eat Guppy babies (White Cloud Mountain Minnows might not) so in a community tank the babies have a very dangerous life. Occasionally one or two will survive in a well planted tank with not too many fish.
"Guppy traps' or similar arrangements are often used to separate the female and save the babies. They are far from perfect. The female may get excessively stressed in the 'trap' and may even die from the stress. If you have a separate tank you can often catch some of the babies soon after birth and transfer them. Another way I have used is to have a very well planted tank, and only put one of two female Guppies in. The females can be kept well fed and if they are available, Daphnia can be continuously present. In these conditions, the females are less likely to eat the babies. After giving birth, the mother fish can be removed. The baby fish will eat the baby daphnia and grow well.
Raising Baby Guppies
Baby Guppies are able to eat normal fish food of small sizes. They do better on a fry food. I greatly prefer the dry fry foods to the liquid ones. To get the best growth out of your babies, some live food is very beneficial. I use Daphnia screened through a coarse aquarium net so only the smaller daphnia are given the babies, although the larger Daphnia will not harm the baby fish and will breed in the tank.
Newly hatched brine shrimp can also be used, if you can get the eggs.
Guppy Hybrids
In some cases interspecific hybrids between Guppies and Mollies occur. It is reported that these hybrids are sometimes fertile, although I have never tested this. Note also that if a cross was done and the babies found to be infertile, this definitely does not prove that this will happen every time. Guppy-Molly hybrids are fairly drab in colour.
Hybrids can also occur between Guppies and the Endler's Livebearer. These are reported to be fertile. Guppy-Endler's Live Bearer crosses are colourful. It would be a shame if the Endler's Livebearer became extinct as a pure species.
The Guppy is probably the easiest fish of all to breed. In fact the only way of being sure that you will not get baby Guppies is to get only male Guppies. Many people do this. The Males are the more colourful. Getting only female Guppies is not a reliable way of preventing reproduction because the Females could have mated before you got them. Unlike with most fish, fertilization in Guppies is internal. This also applies to their near relatives, the Mollies, Platies and Swordtails.
A female Guppy can have more than one lot of babies from one mating, so the mating could have happened a considerable time before birth. The gestation period of Guppies averages about 28 days. This varies with external factors. The water temperature may have an effect. Higher temperatures may shorten the gestation period, and day length also seems to be important, with a longer day length shortening the gestation.
A female Guppy can often become pregnant at as young as two months, having her first babies at three months old. She can the continue having babies every 28 days or so for the rest of her life. The Guppy produces fewer babies in each litter than most fish, but the babies are bigger in relation to the fish's adult size than most fish babies. This tends to give a high survival rate. This coupled with the short generation time means that Guppies can multiply quickly. In some places there are so many Guppies visible in the water that they have been called the 'Millions fish'.
Most strains of Guppy eat their own babies, as well as the babies of other fish. Most types of other fish will eat Guppy babies (White Cloud Mountain Minnows might not) so in a community tank the babies have a very dangerous life. Occasionally one or two will survive in a well planted tank with not too many fish.
"Guppy traps' or similar arrangements are often used to separate the female and save the babies. They are far from perfect. The female may get excessively stressed in the 'trap' and may even die from the stress. If you have a separate tank you can often catch some of the babies soon after birth and transfer them. Another way I have used is to have a very well planted tank, and only put one of two female Guppies in. The females can be kept well fed and if they are available, Daphnia can be continuously present. In these conditions, the females are less likely to eat the babies. After giving birth, the mother fish can be removed. The baby fish will eat the baby daphnia and grow well.
Raising Baby Guppies
Baby Guppies are able to eat normal fish food of small sizes. They do better on a fry food. I greatly prefer the dry fry foods to the liquid ones. To get the best growth out of your babies, some live food is very beneficial. I use Daphnia screened through a coarse aquarium net so only the smaller daphnia are given the babies, although the larger Daphnia will not harm the baby fish and will breed in the tank.
Newly hatched brine shrimp can also be used, if you can get the eggs.
Guppy Hybrids
In some cases interspecific hybrids between Guppies and Mollies occur. It is reported that these hybrids are sometimes fertile, although I have never tested this. Note also that if a cross was done and the babies found to be infertile, this definitely does not prove that this will happen every time. Guppy-Molly hybrids are fairly drab in colour.
Hybrids can also occur between Guppies and the Endler's Livebearer. These are reported to be fertile. Guppy-Endler's Live Bearer crosses are colourful. It would be a shame if the Endler's Livebearer became extinct as a pure species.
