Approximate growth rates of the Guppy.
Please keep in mind that this will vary according to care (especially feeding), and genetics. However, I have included this for general reference. Please note that females may grow much larger than the males.
Male Body length not including tails.
New born: 6 mm
One Week: 7 mm
Two Weeks: 1 cm
One month: 1.5 cm
Two months: 2 cm
Three months: 2.5 cm
Six months: 3 - 3.3 cm
Full grown: 3.5 - 4 cm
to tell the sex of fry The answer is, believe it or not, at one week of age! Just look for the gravid spot which every female has. Use a small magnifying glass and a flashlight. When separating them, if there is a question as to whether a guppy is male or female, put it with males. Keep in mind that there is no urgency to separate them until the male's anal fin begins to look pointed. He cannot inseminate females until his gonopodium is developed.
How soon can guppies multiply
Females mature at about 3 months of age, perhaps sooner in a warmer tank. Males sexually mature somewhat sooner. The males will develop a modified, pointed anal fin called gonopodium, after several weeks. The male with the least desirable traits often impregnates the females, and all chances of controlled breeding is lost. This is a good reason to separate them before the male can develop his gonopodium
there you go
Erin
