I bought some random fancy guppies around 2013. They just multiplied without intervention for years. In 2021 in decided to do some actual selective breeding.
The colony lives in a standard (for Europe) 60cm / 54l / 14gal tank. The juvenile males get transferred to a separate tank and only a few select (somewhere around 3-5) males are living in the colony. Excess females and males (from the other tank) that don’t fit the breeding goal get transferred into my big community tank.
In September 2021 my best males looked like this and I decided to focus on increasing the amount of red in the body.
Now in January 2022, the red content is much bigger and most of the males now have a double sword tail (well, at least some color at the top and the bottom) and look like this:
The females also have started to show some color in their tail and I have now started to select females, too. Only those with color in their tail, ideally with a double sword coloring, are kept.