Guppy Longevity

Older Female
Older Male

My 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

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)

Flukes and Sick Guppies

Flukes and Sick Guppies (8 pages) tackles the problem of why guppies die for “no good reason.” It starts with the author’s discovery of skin flukes (Gyrodactylus species) on her own guppies.  Apparently, these Monogenean parasites have been a major, long-standing pathogen of the guppy (Poecilia reticulata).  The author describes treatments and disease management strategies.  Photo (magnified) shows Gyrodactylus flukes feeding on the outer mucus layer of a heavily infested salmon.

Parasite Surveys

Which parasites are most prevalent in tropical aquarium fish?  My article Parasite Surveys of Aquarium Fish, a compilation of 11 different investigations from around the world, answers that question. Freshwater fish (goldfish, guppies, tetras, etc) were sampled from Sri Lankan fish farms, Swedish pet shops, etc.  Most surveys reported Monogeneans (i.e., flukes) as the most common parasite of aquarium fish–whether healthy or diseased.  For example, 37% of 223 freshly caught wild fish from the Amazon carried Monogeneans, ranging from a 92% prevalence in Angelfish to only 7.4% in Cardinal Tetras.  The ICH parasite was in second place (21% prevalence in the 223 fish), but other studies reported a much lower prevalence of the ICH parasite. Overall, Monogeneans dominated.