Raising Goldfish is really not that difficult. However it does take a little understanding to be successful. First lesson is DO NOT keep goldfish in those so-called Goldfish bowls. You can raise Bettas in them but not Goldfish (Carassius auratus). Keep them in large aquariums, the larger the better.

When selecting your fish for breeding use specimens that are at least two years old, while four to six year olds are better. Always set your standards high when selecting your breeders.

After you have chosen the best you can obtain, now comes the sexing. It is not really that difficult if your fish are in spawning condition. But from time to time even the so-called experts are confused. There are two methods. One is to look for salt type spots on the opercular region and on the first ray of the pectoral fins as an indication of a male. The other method is to determine sex by the shape and appearance of the anal opening. If possible, separate the males from the females to avoid an accident before you set up.

In the fall, feed your breeders live foods, chopped worms, brine shrimp and duckweed. This will help assure healthy breeders and quality eggs when spawning time arrives. The breeders’ water temperature should be kept in the mid thirties to forty degree range for about two months. Feeding them very little or not at all. Then the water temperature can gradually be raised to the fifty to sixty degree range during the pre-spawning period.

Feed them lightly two to three times a week for four to six weeks. Finally, raise the temperature to sixty-five to seventy degrees in preparation for spawning. Breeding can be accomplished by using twenty-gallon long or forty-gallon breeder tanks. The size and type depends on what’s planned and the size and number of breeders being used. You will have a higher percentage of fertile eggs if you use two males to each female being spawned. You can make or purchase spawning mops to use for an egg catching medium.

If everything goes as planned you will notice the breeders rubbing against the mops and each other. At this time the males will begin chasing the females and nudging their heads into the female’s caudal and anal area. The females will begin releasing their eggs and the males will release their milt, fertilizing the eggs. The chase usually begins after a storm or a quick change in barometric pressure. It usually begins in the morning and lasts for four to six hours.

When the spawning ends the breeders will begin eating the eggs. Remove the eggs/spawning mops at this time. Place them in separate tanks with water at the same temperature as the breeding tank.

If using water at sixty-five to seventy degrees it will take around seventy-two hours to hatch. Fertile eggs will be pale amber to pale yellow in color. Infertile eggs will be opaque in color and eventually become fuzzy as fungus develops, remove fungused eggs. To control fungus add methylene blue or malachite green.

When the fry hatch they will be less than one quarter of an inch long. Their bellies will have yolk sacs. This will nourish them for a few days, do not feed them at this time. After that you will need to feed them finely sieved daphnia or newly hatched brine shrimp. Remove uneaten food and use a sponge filter with low turbulence. At two weeks of age you can begin culling unwanted fish by using a magnifying glass.

By Rick Graham. First published in “Tank Topics”, Greater Akron Aquarium Society, Aug/Sept 2001