The wild guppy (Poecilia reticulate), in which the male body and fins are a kaleidoscope of color, is the starting point of all fancy guppies. The first manmade guppy strain was the double swordtail, but the big fancy guppy break through came in the 1950s with the development of the veiltail guppy by Paul Hähnel. One way to create a new guppy strain employs “inbreeding,” but even this takes patience, time, effort and resources.
A hobbyist wanting to develop a single new guppy strain would need a minimum of four tanks: one 10-gallon tank for the adult male and female pair, and three 20-gallon tanks (one for the small fry, plus two grow-out tanks for male-only and female-only fry, kept separately). Water quality in the bare-bottom tanks can be maintained by individual air driven sponge filters and water changes, while temperature should be kept at 68 degrees Fahrenheit (24 degrees Celsius). Ideal water for these tanks is moderately hard and alkaline.
When attempting to produce a new guppy strain, a fixed idea of the new guppy’s body and fin color, as well as caudal fin shape, is necessary. Accordingly, a young male and female that each show some of the new guppy traits are purchased. The guppy pair should be kept together in their tank through the first brood, as the female is receptive to new sperm from the chosen male for just a short time after dropping her fry. The first fry do not usually carry the chosen male’s genes and are therefore not kept. Some four weeks later, the female, plump with her second brood, is moved to the fry tank to drop her second batch of fry and is then immediately returned to the male.
The fry are grown out in their fry tank for about four to six weeks until they are old enough to sex. They are moved to the male-only or female-only tank, and grown on to maturity separately for at least a further four months. Then there is a choice to breed either the best brother and sister guppy, or the best sister guppy back to the father, or the best son guppy back to the mother, depending on what characteristics the young guppies show and how closely they match the new guppy on the drawing board.
First, though, all the tanks need to be emptied of fish, keeping just the two guppies needed for the next phase of breeding. The unwanted youngsters could go to friends or to the fish outlet, either as feeder guppies or (if they are colorful) as fancy guppies for the community tank. Under no circumstance should they be released into local rivers or ponds.
The next round of breeding results in more fry, and some five to six months later, the best male and female guppies are again selected for more crossings until the goal is reached. Producing a new strain of fancy guppies does take time and effort but can be a rewarding project.
Want to read the full story? Pick up the July 2008 issue of Aquarium Fish International today.