How to Have Fantail Goldfish Reproduce

Fantail goldish are a hardy cold water species of goldfish named for their large, fan-like tails and fins. They are often brightly colored with spots and other color markings. They can tolerate extremely cold temperatures and are frequently kept in outdoor ponds because of their ability to survive harsh environments. A group of goldfish will readily breed, so inducing mating is not challenging. The eggs and fry that hatch from them, however, require special care.

Things You'll Need

  • Male goldfish
  • Female goldfish
  • Two fish tanks
  • Brine shrimp
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Instructions

    • 1

      Wait for your goldfish to show signs that they are ready to breed. Fantail breeding season is normally in early spring, but domesticated goldfish that are kept indoors may decide to breed at any time. The female goldfish will become plumper around her abdomen, creating the appearance that she is pregnant. Males will develop small tubes that resemble pimples on the gills and pectoral fin.

    • 2

      Create an optimal breeding environment. Draining the water and then refilling the tank can help to stimulate mating behavior. This is especially helpful if your goldfish have gone several months without any signs of breeding or if you don't want to wait until the spring breeding season. Changing the water is not a necessary step, but will increase the likelihood of mating.

    • 3

      Raise the water temperature so that it is between 70 and 78 degrees Fahrenheit. This is also a good opportunity to test water pH, which should be close to 7. Low pH indicates highly acidic water, while high pH indicates alkaline water. Neither water conditions are healthy for goldfish. If the water appears cloudy, clean your water filter and avoid feeding fish more than what they will eat in 15 minutes.

    • 4

      Allow the goldfish to mate. They will do this on their own without any outside intervention, assuming the conditions are favorable. The female will release her eggs and the male will fertilize them. Male fantail goldfish release sperm directly into the water, but you will not be able to see the sperm swimming to the eggs. The eggs are tiny, gelatinous circles that may be partially white or clear. They typically sink to the bottom of the tank or stick to tank decorations like artificial plants.

    • 5

      Remove the goldfish from the tank as soon as the eggs are fertilized by the male as adult goldfish frequently eat their own eggs. Because the male will fertilize the eggs almost immediately after the female lays them, you should remove the goldfish no more than five minutes after the eggs are laid.

    • 6

      Check the eggs frequently to see if they have hatched. Fantail goldfish eggs can hatch in less than 24 hours if the temperature is above 70 degrees Fahrenheit. In colder temperatures, hatching can take as long as a week. Feed the fish fry brine shrimp for the first two to three weeks of life then shift them to adult goldfish food. You can place fish fry with their parents when they reach adult size.