The gestation period of a guppy usually ranges from 21 to 30 days, with its exact length affected by the following factors:
1. Basic Gestation Period Range
Standard Period: For most cases, it lasts 22–28 days.
Shortest Recorded: When the water temperature is 26–28°C (78.8–82.4°F), some guppies can give birth as early as 22 days.
Longest Recorded: If the water temperature is below 24°C (75.2°F) or the female is pregnant for the first time, the period may extend to 30–32 days.
2. Key Influencing Factors
Water Temperature
The gestation period is shortest (22–26 days) when the water temperature is at the optimal range of 26–28°C.
For every 1°C drop in water temperature, the gestation period may lengthen by 2–3 days.
Female Guppy’s Condition
First-time pregnant females have a gestation period that is 3–5 days longer than experienced ones.
Healthy adult females give birth more quickly; some can complete delivery within 3 hours.
Environmental Management
Maintaining water quality with a pH level of 6.8–7.4 and ammonia levels below 0.02 mg/L helps stabilize the gestation period.
A high-protein diet can shorten the gestation period.
3. Key Signs of Impending Birth
Gravid Spot Change: For common guppy varieties, the gravid spot turns dark black; for albino varieties, it turns orange-red.
Abdominal Shape: The abdomen changes from rounded to square, and the outlines of the fry inside become visible.
Abnormal Behavior: The female tends to hide, loses appetite, and breathes rapidly.
4. Breeding Management Recommendations
Isolation Timing: Immediately isolate the female guppy once a dark gravid spot or square-shaped abdomen is observed.
Post-Birth Recovery: Females can become pregnant again after 1–2 weeks, but it is recommended to limit breeding to a maximum of 7 times per year.
Note: Individual differences may exist among different guppy varieties. It is advisable to adjust management measures based on specific observations.