How to Breed Freshwater Live Bearing Fish

Not only are platies and guppies colorful, hardy little fish that will thrive in a well-maintained tropical freshwater aquarium, but they reproduce with little difficulty. If you want to try your hand at raising these fish, the main problem you will face is preventing the other fish, including the parents, from eating the babies, or fry. With a modestly sized, extra aquarium and some basic fishery techniques, you can ensure optimal conditions for your freshwater fish to breed and for their babies to survive.

Things You'll Need

  • 2 1/2-gallon to 5-gallon aquarium with filter, heater, light and live plants
  • High-quality commercial fish food
  • Fresh or frozen brine shrimp
  • Fish net
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Instructions

  1. Breeding Guppies

    • 1

      Make arrangements to provide homes for the babies, whether with friends who are aquarists or a reputable fish store. Even though you may have room for the first generation, guppies are such prolific breeders that they can soon multiply beyond the capacities of your community tank.

    • 2

      Condition your guppies for healthy breeding by feeding them high-quality, dry fish food supplemented with fresh or frozen brine shrimp.

    • 3

      Keep the water in the aquarium at 74 to 82 degrees, and perform partial water changes as necessary to ensure good water quality.

    • 4

      Observe your guppies closely for the breeding ritual, in which the male circles around the female, spreading his brilliant fins in an elaborate display. Breeding occurs when the male touches his forward-protruding copulatory fin to the female's genitals.

    • 5

      Watch for the development of the dark gravid spot on the female, starting in her belly and moving toward her vent. When the spot becomes very dark and enlarged---usually around the 20th day---move the female to the breeding tank. Gestation usually takes 28 days but can sometimes take up to 40 days. A female becoming very inactive is a clue that birth is imminent. Because females can store sperm for up to three months, she may eventually drop as many as five litters from a single mating, spaced at four-week intervals.

    • 6

      Place the gravid female in a nursery aquarium, lushly landscaped with plants, such as Anacharis, that will provide hiding places for the fry when they are born. Do not use a tank larger than 5 gallons for a nursery tank in order to spare the tiny fry from wasting energy as they search for food.

    • 7

      Remove the female guppy after the birth and replace her in the community tank, monitoring her for signs of stress. Check the fry---they will be hiding in the plants---and remove any that are deformed or on the bottom of the tank.

    • 8

      Feed the fry three small meals per day of baby brine shrimp and flake food formulated specially for babies. Some hard-boiled egg yolk, strained through a cloth, is an ideal starter food for baby guppies.

    • 9

      Perform 25 percent water changes per week in the nursery tank to maintain good water quality. When fry have grown big enough---usually at about eight weeks---introduce them to the community tank.

    Breeding Platies

    • 10

      Use a ratio of three females for each male to ensure the health of the females. If only one female is placed with a male platy, he may chase her to exhaustion, causing severe stress.

    • 11

      Watch for mating behavior, which involves the male persistently chasing one or more of the females, and observe the gravid spot developing on the female near the vent.

    • 12

      Place the gravid female in a nursery aquarium about three weeks after the mating ritual. The tank should be landscaped with plants that afford good hiding places, such as Java ferns, Vallisneria, and Anacharis. Like guppies, platies may eat their young. Remove the female when she has finished giving birth. With platies, this takes about an hour and can result in as many as 50 fry.

    • 13

      Feed the fry baby-brine shrimp and flakes specially formulated for baby fish.

    • 14

      Introduce the platy fry into the community tank when they are large enough not to be eaten by the other fish. Depending on the size of the fish in your community tank, this will usually be when the young platies are about 10 weeks old.