Breeding Guppy (selective guppy breeding)

Breeding Guppy (selective guppy breeding)

The Guppy is one of the most popular livebearers and it is often found in beginner aquariums. Many aquarists loose interest in the Guppy as they move on to more delicate fish species, but quite a few are instead mesmerized by this charming fellow and decide to keep and breed high-quality guppies. Some aquarists even start to produce show guppies for Guppy competitions. These Guppies are very far from the sturdy, no-nonsense Guppy sold to beginner aquarists under the name “Common Guppy” most fish shops.

Through many generations of selective breeding, the wild Guppies developed into what we now refer to as “fancy guppy”.  Guppies happily reproduce in captivity, but if your want to create a strain of high-quality guppies you have to devote plenty of time and effort to the project.


To begin with, make sure that you have high quality fish to start with. If you walk down to your local fish shop and purchase a few of the fairly inexpensive guppies that they offer beginner aquarists you will most likely end up with not-so-good guppies. These guppies can serve as excellent pets for novice fish keepers, but they are not a good foundation for a strain of high-quality guppies. It should also be noted that many fish shops sell “Guppy couples” where the fishes come from completely different strains. The best way of getting high quality Guppy suitable for breeding purposes is to contact a reputable breeder and purchase high quality specimens from him or her. This will save you a lot of time and effort since you will have prime specimens right from the start. If you fail to locate a good local auction there are several reputable guppy breeders to be found online that will deliver fish by mail order.

Once you have found a reputable breeder, purchase a young couple. The risk of deformities will increase if you let old Guppies breed. Old male Guppies are also known to have trouble breeding.

Before you engage in selective breeding, it is important to develop a plan. A lot of breeding programs have gone astray in the hands of indecisive aquarists. Set goals to begin with, such as increasing the size and adding color. Then decide to breed a certain number of generations focusing on size, before shifting over to focusing on color. If you have decided to focus on size, do not suddenly pick a small fish as parent fish simply because it shows nice colors. If you absolutely can’t stand the idea of not breeding the colorful fish, it is advisable to set up a separate breeding aquarium where you can focus on perfecting that color without interfering with your first breeding program.

Crowding can lead to stunted growth. Never keep more than 8-12 guppies in a 10 gallon (roughly 40 L) aquarium. Unless you have a lot of friends to unload guppies on, you will be forced to cull each batch to keep the number of fish down.

Water quality
Ideally carry out a small water change once a day, rather than a big weekly one. Keeping the water quality up and simultaneously avoiding rapid changes is desirable.

The standard recommendation for Guppies is 65-68 degrees F (18-20 degrees C), but in a breeding aquarium you should increase the temperature to 74-78 degrees F (23-25 degrees F).

Really young Guppies can be fed microworms and newly hatched brine shrimp. Juveniles will appreciate larger brine shrimp and live food. 

It is better to give your fish several small servings per day than one or two big ones. If you want your Guppies to grow as large as possible, it is important to feed them a lot during the first few months of their life since this is when they go through a period of very rapid growth.

Select parents wisely for each generation
Do not let your Guppies breed randomly. Select your best males and females and only allow them to breed. Harem breeding is not recommended. Collect the best specimens from 1-2 batches, and then move on to the next generation.

Selecting the right male Guppy
Some Guppy breeders automatically allow the first male that matures to breed, but this is not advisable. The first male might not be the best one, and it is also true that the first Guppy that reaches sexual maturity rarely grow as big as the more slowly maturing males.

Selecting the right female Guppy
The right female is not necessarily the best looking female, since you need a female that will produce great offspring – including great male offspring. Breed each of your various types of females to the same good male and raise the different batches separately. This way, you will know which type of female that you should pick for future generations. Use the female type that has produces the very best male Guppies.

Related strains
It is recommended to keep a related strain of Guppies. Too much interbreeding can be harmful for a strain; it is therefore a good idea to occasionally cross two related strains. Preferably use related Guppy strains of the same color. Interbreeding will lead to a high percentage of deformed fish, e.g. fish with hernias or bent spines. A low fertility rate is also a warning sign of too much interbreeding.

With time and patience the mulberry leaf becomes silk
If you want to breed supreme quality Guppies, you have to be patient. Improving the quality of a strain is a slow and gradual process, and it can sometimes be easy to forget about the long row of tiny improvements that you have achieved from generation to generation. (Photographing is a good way of remembering!) Roughly speaking, you can not expect more than 5-10 percent of each batch to even have the potential of being better than their parents. Picking the right fishes for future breeding and providing your Guppies with ideal care is therefore very important.

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