Guppy Genetics

Revision of 2020 Guppy Genetics Article

I revised my 2020 article ‘Breeding Guppies: Genetic Pitfalls and Successes‘.  Revision containsapril-18_2018-1 same basic material, but I simplified article.  I spent more time discussing popular mutations that can perplex beginners.  And I down-sized a complicated discussion on the genetics of swordtail guppies.   It was not that relevant in successfully outcrossing my beautiful delta-tail females (Photo) with male swordtail guppies.   These outcrosses were wildly successful and I had no trouble breeding out the swordtail trait.

Guppy Longevity

Older Female
Older Male

My 2022 revised article Guppy Longevity (10 pages) answers the question of why fancy guppies don’t live that long.   It puts much of the blame for guppy fragility onto the common practice of using only young fish as breeders.  The long-term result is detrimental genetic changes. Since I started using only older fish as breeders, I’ve increased the longevity of my fish from ~6 months to over 12 months.  Photo shows a 15-month old male and female.   Still room for improvement, but this is progress.  

Small-Scale Guppy Breeding

How to breed nice guppies in just 8 planted tanks

Holding Tank
Male guppies that I have bred and raised in my small-scale breeding operation

This 2022 revision of my article Small Scale Guppy Breeding describes how I breed fancy guppies in just nine tanks.  Articles covers the basics, but it contains new, vital information on guppy reproduction.  Learn why I keep “chase” females with my juvenile males, why one female accepted and quickly mated with a new male but her full-sister rejected him…  Learn the pros and cons of separating the sexes, how I breed for fitness…  Overall, the article celebrates the guppy’s genetic trait of color polymorphism.  Unlike breeding methods that emphasize strain uniformity, I work with the guppy’s natural tendency to produce different color patterns (Photo).  This not only makes guppy breeding more fun but avoids inbreeding problems and genetic weaknesses.

Guppy Genetics 101

Genetics of breeding fancy guppies for fitness, disease resistance, and beauty


Breeding Guppies: Genetic Pitfalls and Successes (10 page article) describes my experiences with crossing various guppy strains–Metalheads, Blue Grass, pet shop guppies, swordtail guppies, etc.  Avoid the genetic problems I encountered as a beginning breeder.  Follow the story, which includes basic genetic explanations, to a happy ending–the creation of novel and beautiful phenotypes.  (Article revised March 2022)