How Do Guppies Breed? A Detailed Explanation of the Key Points of Breeding Techniques

Guppies are ovoviviparous fish with strong reproductive capacity and early sexual maturity. After 3-4 months of rearing, the fry enter the mature stage and can reproduce. The timing of sexual maturity is closely related to water temperature and rearing conditions.

When breeding guppies, choose a relatively large aquarium, keep the water temperature at 26°C, and maintain a pH of 6.8-7.4. At the same time, plant more aquatic plants, then introduce the breeding fish at a ratio of 1 male to 4 females. After the fish come into heat, the female's abdomen gradually swells and a black gravid spot appears; the male then constantly chases the female, and when the male's gonopodium is inserted into the female's vent, it releases sperm for internal fertilization. When the female's gravid spot becomes large and black and the anus protrudes, she can be netted into another aquarium to await delivery.

The temperature in the birthing tank should be 1-2 degrees higher than the original water temperature, and moss or aquatic plants should be placed at the bottom of the tank to give the fry a place to hide. After the female gives birth, she must be removed immediately to prevent her from eating the fry. Alternatively, use plastic sheets to form a funnel-shaped isolation wall immersed in the water, place the birthing female in the funnel, and let the fry fall through the opening at the bottom of the funnel into the water outside it, so the female cannot eat the fry.

Guppies give birth once a month. Depending on the size of the female, each brood can be 10-120 fry, and the annual output is considerable, hence the name “million fish.” When breeding, note that broodstock kept from the same batch should not exceed three generations, to avoid continuous inbreeding that leads to variety degeneration, making the offspring smaller and smaller with shorter caudal fins. It is best to introduce fish of the same variety for purposeful outcrossing, to prevent degeneration of the strain and achieve the goal of variety improvement. However, guppies have a very short lifespan, generally only 2-3 years. The first brood is usually relatively small, about 10-80 fry; the second brood is about 80-120 fry. Prices range from a few yuan to several dozen yuan, or even several hundred yuan per fish.

Guppies may fight over territory in a narrow area, and this can lead to the death of the fish, so when space is limited, it is suitable to keep them singly.