For my method, you buy or take a male and a female guppy with a characteristic that you like. A characteristic can be something like a pattern, a color, a tail shape, etc. Then you breed them and raise the fry together until they’re about 3 to 4 weeks old.
Then, you want to start separating them. You want to separate the males and females [the best way to tell them apart is their dorsal fin] do you want to check every day to make sure that you have separated every single male and female.This is crucial so that the females don’t get pregnant with males that you reject [not showing your characteristic]. Then, you raise them up till you’re sure they are mature, which is around three months.
Once you think they are mature, take the mail that shows the characteristic that you’d like the most, and cross him with one of his sisters that shows the trait also and at the same time should have a good round belly.
You breed them and then you raise up those fry. Now it is time to add new blood. I like to think of this as a time to add a new characteristic and make any adjustments that you would like.
Keep the female from the same blood as before, and buy or take a new male that is not related to the female guppy that you have selected.
Cross them and repeat. I like to do this for 6 to 8 generations and sometimes I even do it for up to 12.
Once you’ve reached the point where you think you have perfected your characteristic, put the guppies that you have perfected in a main tank, such as a 20 gallon or more, so they can go crazy. you can take out any of the odd ones that you want to reject and my preferred way of doing it is not to kill the rejects but instead to go and give them back to a fish store as a donation. that way, they can hopefully live a happy life with someone else who may or may not wanted to breed that strain that you have by mistake created.
This selective breeding process is a similar process to line breeding, and it requires a lot of tanks and effort. But above all, it requires a buttload of patience.
A few things to note:
- The females you select MUST be virgin
- Once you to start do not give up
- Once the female is pregnant, separate her from the male to reduce stress on her, and the fry
Here are some images if that was confusing: