The body size of guppies is influenced by multiple factors such as species, gender, and breeding conditions. Here’s a detailed analysis:
I. Basic Size Range
Male Guppies
Body length typically ranges from 3 to 5 cm.
Caudal fins are well-developed, accounting for over 1/2 of the body length. Some species (like Swordtail Guppies) can reach 4–4.5 cm including the tail fin.
Female Guppies
Body length generally ranges from 5 to 7 cm.
Rounded and plump body shape, with caudal fins proportionally shorter than those of males.
II. Key Influencing Factors
Species Differences
Mosaic Guppies: Males 3–3.5 cm, females 4–5 cm.
Metal Guppies: Males about 3 cm, females up to 6 cm.
Breeding Environment
Water Temperature: The optimal range is 22–28°C. Low winter temperatures (below 20°C) can reduce growth rates by over 30%.
Space Density: Fry need to be divided into tanks promptly. 30–50 fry per tank is ideal, as high density inhibits growth.
Water Quality Management: Changing 50% of the water daily accelerates fry metabolism, shifting to 1/4 weekly after reaching adulthood.
Nutritional Supply
Live prey (such as water fleas and brine shrimp) promotes development better than artificial feed.
Food scarcity can delay adulthood to 6 months (normal is 3–4 months).
III. Special Cases
Artificially modified species (like Tuxedo Guppies) may exceed typical size ranges.
Extreme breeding conditions can lead to dwarfism (<2.5 cm) or gigantism (females >7 cm).
Recommendations: Optimize growth by controlling water temperature, feeding rationally, and managing tank division. For breeding high-quality individuals, choose parent fish with clear bloodlines.