Breeding goldfish
It’s not impossible to breed your goldfish, but it’s not as easy as breeding rabbits or gerbils.
The reason is that goldfish lay eggs in the water, rather than giving birth to baby goldfish. These eggs must be protected until they hatch, and the tiny baby fish (called fry) raised using special baby fish food.
The eggs are vulnerable to infection, and parents will give you no help, either. In fact, they may even eat the eggs, and so the eggs and baby fry will need their own aquarium or pond.
On the other hand, you can potentially raise dozens or even hundreds of baby goldfish from just one spawning, if you’ve got the time, resources and commitment.
You might even get the bug, and try and develop your own line of fancy goldfish. After all, no fancy goldfish occur naturally in the wild - they have all been developed by many years of selective breeding.
Key steps in breeding goldfish
Click on the links below (where available) for information on that specific breeding step.
- Choose the parent fish for breeding
- Separate the male and female goldfish
- Feed your brood stock to improve their condition ahead of breeding
- Prepare the special aquarium that you will use to raise your goldfish fry
- Reunite the male and female goldfish in early Spring in the breeding aquarium
- Watch your goldfish making love! Then remove the parents, and wait for the eggs to hatch
- Feed the babies baby brine shrimp, switching to other foods as they grow
- Maintain good water conditions in the fry aquarium
- Cull weak or deformed goldfish in order to preserve the genetic line
- As they grow, divide the goldfish out into more aquariums or ponds to avoid overcrowding.
We’ll be writing separate entries for each of the steps above in the next few weeks, so please do subscribe to the Goldfish Care Guide to stay informed.
Click here to learn more goldfish secrets!
Filed in: Breeding
Dec 26th, 2008 at 1:52 pm
Yes breeding goldfish is something all goldfish owners will want to try or see happen sooner or later. The only thing if not done correctly and perform proper measures that need to be done some people may be disappointed. Biggest thing is removing the parents as you mentioned. Goldfish will eat up all the eggs or at least try! People will be lucky if they have some left. Another thing with goldfish breeding is that people should add fungus medication into the water which is specifically meant for protecting the eggs from fungus. This will help with results on how many eggs that will hatch from your goldfish breeding. I remember when I first got into the hobby and my godfish just finished breeding. Days later all goldfish eggs were all covered in fungus and I got absolutely nothing from the batch. That should be something that people think about as well and maintain excellent water quality as mentioned.
Owen you have a great goldfish care blog! Keep up the great work.
Happy Holidays and Best Wishes in 2009
Sincerely,
Jamie Boyle
The Goldfish Guy
Apr 29th, 2009 at 5:53 am
how do you know what sex of goldfish you have
Apr 30th, 2009 at 1:56 pm
Yes, i ask the same question, how can you tell the difference between sexes?
May 25th, 2009 at 8:22 pm
how do you tell the sex of goldfish.
Jun 7th, 2009 at 4:23 am
I am no “certified expert” on the matter but have learnt a lot through reading and experience. Hope some of this may be useful to other fellow hobbyists.
There’s a lot of info on ways of sexing goldfish (do a small search on the net and you’ll be overwhelmed).
1. Males have tubercles on the gills during the mating season (hard to distinguish at times and females sometime display this characteristic as well, just as women with hypertestosteronism & hirsutism)
2. Body/belly size when egg-laden (well, you may as well have a very fat-looking male…)
3. Shape of the anal orifice (often hard to distinguish, needs a well-trained eye, larger and elongated in females, some sources distinguish as concave/convex shapes etc).
4. Behaviour: who chases and who is being chased? (In my opinion the most reliable)
The key is in long hours of OBSERVATION. A combination of two or more signs makes it more likely that you are not mistaken. Of course, the best way will be when you actually see them breeding… Or put them in the company of fish with known sexes…
For cleanliness of the water for raising the fry.
The larger the water quantity you have in your aquarium the better (I prefer no less than 150 litres). Easier to maintain. I see no need to make frquent water changes if you have good biofiltration and large surfaces for bacteria to grow on (having some sort of trickle filter will help a lot).
Medium to large size gravel will easily trap excess food for further decaying, an abundance of both rooted and floating plants is a must. It will increase the surface AND clean the water (do not forget about proper lighting, otherwise the plants will give off mor CO2 than O2 and will start to decay).
Treating the water with methylene blue before and after hatching helps to reduce fungal infection. Nevertheless, you will still have some eggs (often unfertilised) and fry (visible fin rot) lost to fungus. But if you have saved the batch before being devoured by the parents, you will still have hundreds or even thousands of fry to select a few from.
Last but not least, add some ramshorn & trumpet snails. They do a great job in cleaning the debris. Do not worry about them eating fish eggs. Have never seen them do that, may be they do, but considering the quantity of eggs this should not be a worry. If your aquariums get crowded with snails you can always collect a handful of the larger ones and feed them to your adult fish after crushing. They make good fresh live food for conditioning the females…
To feed the fry.
No problem if you have no brine shrimp eggs to hatch… Have never done this myself (none around where I live).
What I do instead:
(Of course you start feeding in 2-3 days after hatching)
1. Put some banana peels in a bottle of aquarium water under the sun to grow infusoria (better have several bottles prepared before the eggs hatch, they need time to grow) I filter the water through several layers of gauze (after a week or when the water gets cloudy) and squeeze the gauze in the aquarium or throw it in the return outlet of my trickle filters. You can do the same with dried grass or hay. If you have a trickle filter, do not clean all sections at a time. This will greatly reduce the amount of nitrifying bacteria and your ammonia will jump to toxic levels at once. Also, lots of infusoria grow in the debris in the filter and some will end up in the aquairium for the fry lo lunch on.
2. egg yolk as everybody do
3. 2-3 pinches of flour in a cup of water. Add some dry yeast and put it on the lamp to keep warm. The yeast will get activated in no time. You can feed this (after mixing) with a syringe. Don’t worry about your water getting cloudy, it’ll settle down soon and the bacteria+snails will do the rest. Yeast supplies ample vitamin B to the fry and competes with harmful bacteria and increases the immunity of the fry. Prepare some new in 2-3 days as the previous one fouls.
4. Keep a small (10L) non-filtered but aerated aquarium (or jar) in a sunny place, add some fish food (I also add a very small amount of potassium nitrate and sodium polyphosphate to speed up the process) and you will have a green algae bloom. Pour a couple of cups of this water to your fry. They love it.
5. If you ever buy fresh fish for eating and clean it yourself keep any eggs (caviar) that come out of the belly in a flattened nylon pack in the freezer (you can easily crush it to smaller pieces when frozen). After thawing a small piece you can crush it between two glass plates into a milky mixture… Lots of proteins and fat for the fry. Feed this when the fry are some 10 days old.
6. In 2-3 weeks you can start feeding them powdered flakes or dried daphnia or any other adult fish food for the matter.
7. Do a weekly 20% water change. Ordinary tap water will do (no matter what everybody says). No need for special treatment if you keep the water for a week or so. I keep an 80 litre barrel for the purpose.
As you see goldfish are not swordtails or guppies… They need a lot of volume and space. So if you are planning to breed and raise fry you have to plan ahead and have several large well-filtered aquariums. Caring for them is quite an amount of physical work. Nevertheless it is rewarding for those who really love fish. Getting a large batch of fry to be able to select from a few that are really worth IS in itself a VICTORY and SATISFACTION. Believe me, I am the grandpa of more than a thousand fry in a 200L baththub and a 150 aquarium at the time I am writing… IT FEELS SOOOO GOOD
Arshak Davidian
Stepanakert-Mountainous Karabakh
Jun 14th, 2009 at 2:45 am
if not breeding gold fish how do you know male from female? and also i have a greenspotted puffer fish and i had it in the tank with the gold fish and of course it attacked the gold fish and tore some of there fins off but now the goldfish are seperated from the puffer and their fins are growing back . is it possabile fo their fins to grow back?
Jun 17th, 2009 at 1:34 pm
Hi, i came home and one of fishes had something long at the back of it, i am no fish expert and i got worried that he may be sick. The long trail behind was like a greyish colour and now its at the bottom of the tank. Do you know what this was?? Im worried if its laid eggs and i would like it if teh fishes ate them,
Jun 17th, 2009 at 1:35 pm
sorry i meant i would not like it if the fishes ate them
Jun 19th, 2009 at 5:51 am
Nazia’s question of June 17th.
The trailing grey is its poo - faeces.
nick
Jun 28th, 2009 at 4:31 pm
MY HUSBAND AND I HAVE A VERY SMALL GOLDFISH POND. WE’RE IN NEW ENGLAND BUT IT’S DEEP ENOUGH FOR GOLDFISH TO SURVIVE DURING THE WINTER, ALTHOUGH WE USE A HEATER AT TIMES TO MELT THE ICE. WE HAVE GRANDFISH WHICH HAVE OBVIOUSLY SURVIVED AT LEAST A FULL YEAR IF NOT LONGER BECAUSE OF THE SIZE! HOWEVER, THEY’RE BLACK OR AT LEAST DARK GRAY. WILL THEY TURN GOLD OR AT LEAST RED? WE ONLY HAVE TWO LARGE ONES OF EACH COLORING AND THEY’RE AT LEAST 7 INCHES LONG. THANK YOU FOR YOUR BLOG; WE DID NOTHING SPECIAL AND NEVER EXPECTED THIS ALTHOUGH WE’RE PLEASED AS CAN BE.
Jul 3rd, 2009 at 7:06 am
Could someone please help me? I have a small pond with two goldfish in the garden, then just yesterday, I noticed a lot of
babies (fry), do the parents eat their babies as well as the eggs? If they eat the fry, is there a special container to buy I can keep the babies in from harm, until they maybe reach a certain size, where the parents stop eating them?
help very appreciated,
thank you,
Andrea Steinke
Jul 3rd, 2009 at 9:23 am
If a goldfish is bellyup at the water surface for a few days…does it mean it is dying?
Jul 19th, 2009 at 9:25 am
cathrine its dead ! sorry
im gonna start breding mine :):)
Jul 22nd, 2009 at 1:43 am
if it is time for the goldfish to spawn, is it better to help them (hand spawning) or just let it be?
Jul 27th, 2009 at 4:36 am
hello! i am najum i want to say your website is excellent and i have 1pair of goldfish total in aquarium 8fish my goldfish separate in how time ?
Aug 18th, 2009 at 3:02 pm
We had 7 adult goldfish in our livestock 300 gallon stock tank. They have been there for about a year. One day we went out to feed and saw about 30 babies. Boy were we surprised to see babies. This has been fun for the kiddos to see 1) how the fish really do “grow” to the size of their environment (we do have an aquariaum in the house and put 4 fish in there the same time we did the 7 in the stock tank. The ones in the house are 2″ long and the ones in the livestock tank are 10″-12″ long) and 2)seeing the babies and all the colors that they are. The adults are orange/white or orange, or white, the babies are orange/white/black, orange/black, orange/white, or white/black, so it has been really fun
Sep 4th, 2009 at 1:30 pm
Hi,
I just got 3 5″ inch goldfish and 3 4″ inch Chubinke( I think that is what they are called) and 5 small feeder goldfish for my 1200 gallon pond. I see the larger ones sometimes go to the surface and open they’re mouth are they eating or getting air? I havent seen the small ones and I dont know if they are ok or not. Is it normal for them to come to the surface off and on to eat or what ? They seem healthy otherwise and its hard to see in the deeper water. and I didnt get Koi cause I have been told that they can be more messy and eat my plants up, I do see the Gold fish nibble a little off them but nothing major. How many goldfish should I be comfortable supporting in a 1200 Gallon pond?
Sep 17th, 2009 at 6:42 am
One of my fish spends a lot of time on it’s side at the bottom of our small pool - only seems to wake up at feeding time. It is also misshapen on one side. Any ideas?
Ted
Sep 24th, 2009 at 1:15 pm
hello, can you please help me, we have several eggs that we have seen one of our goldfish laying the eggs and we separated her from the rest, after she was done spuring the eggs, we put her back with the other 12 goldfishes. Now my question is how long before the eggs hutch, there are a bunch of like hard shell little eggs on the bottom, how long before they hutch and do we have to keep the water moving with the filter? please let us know we are anxious to see if the baby fish will be born
thank you,
Oct 11th, 2009 at 12:35 pm
how do i know which are male or female?
Oct 23rd, 2009 at 9:05 am
I have like 22 goldfish which r male or famale some r fat can u help out
Oct 24th, 2009 at 3:10 am
here are some links to tell the sexes of goldfish, and in a tank over 200 gallons it is literally ecstatic for the goldfish, and lot’s of hiding places needed for breeding
Oct 24th, 2009 at 3:12 am
Goldfish Tips - Finding Out The Gender of Your Goldfish
Can You Tell The Sex Of Your Goldfish
WikiAnswers - How do you tell the gender of a goldfish
How can you tell the gender of a goldfish? | Answerbag.com
How do you tell the gender of a goldfish? - Yahoo! Answers
Breeding Goldfish and Raising Baby Goldfish Fry.
How can you tell the gender of your goldfish? At what age are they …
Diary of a Goldfish: Sex and Gender: An introduction.
Jan 12th, 2010 at 2:29 pm
my daughter got some goldfish at christmas 4 her new dora tank.one of them seems 2 be laid on its side at the top of the tank.does this mean its dyin??
Feb 1st, 2010 at 8:21 am
I have a 65 gallon hexigon tank and a wet dry filter but it is sucking up the small goldfish. What type of goldfish, size and amount should I get?? I would like to breed them also……thank you