How to Breed Guppies

Select your breeding stock

For you first attempt at breeding guppies, fish purchased from your local aquarium will be perfectly suitable. As you get more serious or if you are interested in breeding for show then breeding stock can be purchased directly from a specialist breeder. Aquarium brought fish are generally bred from the same gene pool by aquarium shop owners, this can lead to undersized and dull fish as you continue to breed from the same gene pool, you can avoid this by purchasing your fish from different sources.

The male guppy should be your most striking guppy and the specimen you would most like the new offspring to resemble. Females should be compact with a thick tail and brightly colored tail fin. If the fish you have chosen to breed are related the offspring will resemble their parents more than if the fish where not related.

Setup the breeding tank

The best size tank for breeding is around 10 gallons, you could go as small as 5 gallons if you don't have the room for a larger tank. Guppies should be kept in water temperatures of 65-68 degrees F (18-20 degrees C) but for a breeding tank the temperature should be increased to 74-78 degrees F (23-25 degrees C). Leave the base of the tank gravel free and install some floating plants like Java Moss for the newborn fish to hide as mothers often eat their own young. Cover the filter with panty hose as they can easily suck up the small newborn fish.

If you don't have the space or money for a dedicated breeding tank you can use a floating breeder box. Floating breeder boxes are small plastic containers that you can place in an existing fish tank. They have a V shaped groove at the bottom with a small slot that allows newborn fish to slip into, this prevents the mother fish or any other fish in your tank from eating the young.

Place breeding fish into tank

Once you have established your breeding tank place your selected male fish and 2-3 females in the tank. You are best to put 2-3 females as this will stimulate the male more than having a solitary breeding partner and a selected pair of fish may not always become a compatible mating pair. When mating is about to commence you will notice that the male performs a dance like movement in front of the females to attract their attention. The fish will then come together and the male will insert its anal fin into the female for fertilization.

You will be able to tell when a female has become pregnant as the dark spot on the fishes belly will become larger and darker in color. This spot is known as the 'gravid spot' and is in fact the eyeballs of the young fry inside the mother. Once you have confirmed that a female is pregnant you should remove the male fish from the tank. The gestation period for a guppy is about 30 days, the female will generally give birth around 3 weeks after you notice she is pregnant.

Prepare tank for birth

To prepare the tank for birth you should remove about 50% of the water and check that your water temperature and Ph levels are correct. Ensure the expecting females are well fed, worms and brine shrimp are good sources of food. Once the female has given birth they should be returned to there regular tank to keep the fry safe.

Raising the guppy fry

The newborn fish will be looking to feed almost immediately, the best food at this stage of their life is the ground up fish flakes. Once the fish have grown slightly it is good to introduce more nutrition into their diet in the form of newly hatched brine shrimp and small blood worms. A cooked egg yolk finely diced is also a good source of protein for growing fish.

Any fish that don't survive should be removed from the tank as soon as possible to prevent disease. Once your new guppies are around 1-2 months they should be large enough to safely place in the tank with your other fish.