How to Breed Common Goldfish

Goldfish were developed by the Chinese around 400 AD. These fish are hardy, but require well filtered water and nutrition. Live foods like brine shrimp and earthworms are ideal for conditioning goldfish prior to the breeding season. Goldfish are normally in their prime during their third year and spawn as the temperature of the pond water becomes warmer. These fish can be sexed at this time by the physical changes that occur in their bodies.

Things You'll Need

  • Goldfish pond
  • Pond heater
  • Mature male and female goldfish
  • Adult brine shrimp
  • Earth worms
  • Spawning mop
  • 10-gallon aquarium
  • Sponge filter
  • Aquarium heater
  • Newly hatched brine shrimp
  • Daphnia
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Instructions

    • 1

      Set a pond heater to between 55 and 60 degrees F and place it into the pond during fall to raise the water temperature during the pre-spawning period.

    • 2

      Feed your breeding stock live foods, such as brine shrimp and diced earthworms during this time, to condition them for breeding. Feed two to three times per week during the last six weeks before spring.

    • 3

      Adjust the pond heater to between 65 and 70 degrees F at the beginning of spring.

    • 4

      Place a spawning mop into the pond. These mops, which are made from numerous strands of acrylic yarn tied together at the top end, can be purchased from your aquatic dealer. The female goldfish will swim into the mop and deposit her adhesive eggs on the yarn.

    • 5

      Watch the goldfish closely. Males will exhibit raised, white tubercles on their operculum, or hard gill covers, and along the first ray of their side fins.

    • 6

      Look out for fish that have filled out and have taken on a plump appearance. It is easier to view the fish from above. These are gravid females with eggs or roe developing within their bodies.

    • 7

      Take note of the fish's behavior. Females which are ready to release eggs will stay in the vicinity of the spawning mop and will swim through and around it.

    • 8

      Pay attention to the male fish which are interested in the gravid females. These fish will swim repeatedly into the abdomen of a female and will drive the female against the sides of the pond, to persuade her to release the eggs.

    • 9

      Fill a 10-gallon aquarium with water from the pond and place a heater, set at the same temperature as the pond, into the tank. Place a sponge filter into the aquarium.

    • 10

      Wait for the females to lay their eggs in the spawning mop.

    • 11

      Remove the mop from the pond and place it into the 10-gallon aquarium.

    • 12

      Observe the eggs hatching after about 72 hours have passed.

    • 13

      Use a magnifying glass to see the fry, which are less than one quarter of an inch long and will be nourished by their yolk sac for the first two days.

    • 14

      Feed newly hatched brine shrimp or daphnia from the third day. Feed three times daily and add sufficient live food to sustain the fry between meals. Brine shrimp and daphnia are available from your aquatic dealer.