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FAQs About Goldfish Reproduction, Breeding

Related Articles: GoldfishGoldfish Varieties Goldfish Systems, Goldfish Disease, Pond LivestockingKoi, Pond Fish Breeding

Related FAQs:  Pond Fish Breeding, Goldfish 1, Goldfish Behavior, Goldfish Compatibility, Goldfish Selection, Goldfish Systems, Goldfish Feeding, Goldfish Disease

Re: Breeding Goldfish
<<Will tubercles show on the males and the females fill with eggs as soon as these fish hit their breeding age?  Do you think that any fish store will take my 'good quality' goldfish to sell (how much per fish do you think?)?  You have been most helpful with my problems>>
<Please read here: Breeding Goldfishes  Bob Fenner>

New Print and eBook on Amazon

Goldfish Success
What it takes to keep goldfish healthy long-term

by Robert (Bob) Fenner

Gravid black moor in trouble!    12/20/13
Hi Neale (and crew):
<I will forward this msg. to Neale; but in case he's busy w/ the holidays, I would go forward with the increased temperature and Epsom use. Bob Fenner>
I have a question regarding a little black moor- she has been gravid for quite some time and has not released her eggs. She has released eggs three times between June and September so I am positive that she is gravid and not suffering from Ascites. I was expecting her to release the eggs about 6 weeks ago as she is as fat and square as she was the last few times but nothing has happened. I have been monitoring her quite closely and notice that her belly has been getting progressively mushier- and I fear that the eggs may be deteriorating: I lost a gorgeous Oranda to infected eggs and don't want a repeat.  A frantic slew of questions: Is there something I can do to help her release the eggs? Would Epsom salt or a temperature increase do anything? I do have a known male in another tank that I could put in with her if I absolutely had to (I really don't want fertilized eggs).
Would gently massaging  her sides help? Should I consider treating the mushy belly
with antibiotic food?  
Thank you and Happy Holidays to you!
Gina de Almeida
Gravid black moor in trouble!    /Neale       12/21/13

Hi Neale (and crew):
I have a question regarding a little black moor- she has been gravid for quite some time and has not released her eggs. She has released eggs three times between June and September so I am positive that she is gravid and not suffering from Ascites. I was expecting her to release the eggs about 6 weeks ago as she is as fat and square as she was the last few times but nothing has happened. I have been monitoring her quite closely and notice that her belly has been getting progressively mushier- and I fear that the eggs may be deteriorating: I lost a gorgeous Oranda to infected eggs and don't want a repeat.  A frantic slew of questions: Is there something I can do to help her release the eggs?
<Not for certain.>
Would Epsom salt
<May help, but if the eggs are dead and decaying, the problem will be bacterial infection and treatment will be more complicated. An antibiotic certainly, and possibly a trip to the vet for extra help or even surgery.>
or a temperature increase do anything?
<Only if the water is very cold, below 10 degrees C. At room temperature Goldfish should be happy and healthy.>
I do have a known male in another tank
<Could help.>
that I could put in with her if I absolutely had to (I really don't want fertilized eggs).
<Least of your problems.>
Would gently massaging  her sides help?
<Possibly, bit just as likely to cause damage to internal organs.>
Should I consider treating the mushy belly with antibiotic food?  
<See above.>
Thank you and Happy Holidays to you!
<And likewise to you, cheers, Neale.>

sick Oranda.. & repro. f'      9/20/13
I was wondering if you could give me some advice on my female Oranda,.. I have had her for 9 years,, She as been well up to about 4 days ago..  I noticed she shed some eggs, then after that day she hasn't eaten  and has this long white stringy looking skin type of poo tube.. But with no poo in it......The stringy thing releases after a day or so then it starts to come out again.........
<Part of the egg shedding; not to worry>

 I took her out of the tank to see if she had anyhting stuck in her throat.
But there is nothing....She is swimming and breathing Ok. But my worry  is she is not eating...... it has now been five days.... As I picked her up I noticed a creamy white substance coming out of her bottom..........
<Nor re this>
 I have spoken to  two different people at different fish stores. One said she may have a tumour and I should euthanise her............
<What? No>

The other said she could be going through a healing process after spawning because of her age...... and  If  she's not eating in  7 days use salt....
Which he didn't really recommend''..
<Perhaps a modicum of Epsom. Please read here:
I hope you can help me I don't really want to lose her.........
Thank you Jan Barker..........
<Cheers, Bob Fenner>
Re: sick Oranda..   9/22/13

Dear Bob.
I want to thank you for your very useful information.. It's nice to know there are people like you out there.
If I had taken notice of my so called fish expert friend at  the pond shop... My lovely girl would be dead now. She has started to eat a little thank goodness I have been putting fry food in the  water and she must have
been getting some goodness from it.. The pooless tube is still coming out of
her bottom... Do you have any idea how long this can go on for ??? and is it
doing her harm.......
<A few more days and no harm whatsoever. There are some folks (even here) that might suggest using a modicum of salt/s; but I would do nothing here period>
Thank you again, I am most grateful..
Jan Barker.
<Glad to set your mind to ease. Cheers, BobF>

Re My fish     9/30/13
Dear Bob
<Hey Jan>
I wanted to send you  a picture  of my now  well, lovely Oranda... At least I think she is  an Oranda I got her in a mixed bunch 9 years ago as a baby....
I was very grateful for your useful information..
Imagine putting that lovely face in the freezer as,,, My so called expert fish keeper suggested.
Thank you again .Jan Barker..........
<Life to you my friend. BobF>

Goldfish laid eggs in aquarium; want to ensure best care for fry    9/18/13
Hi WWM crew,
On Saturday night, I found my Ryukin and telescope chasing my black moor all around their 50 gal aquarium. Knowing that goldfish lay eggs into plants, I pulled up the live plants (Amazon sword and Elodea) from the gravel and floated them at the surface. Starting at midnight, the black moor started laying eggs in multiple batches into the plants. I put a mesh breeder into the tank and scooped up about 20 eggs using it. The rest were eaten by the other fish or fell to the ground; I did a thorough gravel vacuum in the morning to prevent any fungus issues. The eggs I caught have remained in the mesh breeder floating in the 50 gal.
Yesterday, I saw that the eggs had eyes, and my boyfriend called me a few hours ago and said that it looks like they are now beginning to show signs of a tail. I was reading through old WWM entries on this to try to get as much info as possible, and noticed several entries stating that it was highly unlikely that goldfish will spawn in an aquarium. But not only did this happen in my 50 gal; the two male Orandas in my 36 gal are also showing breeding tubercles (though there is no female fish in that tank at the moment). I wonder why I am so lucky? They are fed a varied diet of Hikari pellets, Tetra flake food, Hikari frozen Spirulina/brine shrimp, and dried bloodworms. I have only been feeding the varied diet (as opposed to Tetra flake food only) for the past few months in response to research into goldfish nutrition; is this likely what prompted the spawning? I live in California, where there is little change among the seasons. I have not witnessed this before and it is very exciting. I just want to make sure that I am doing everything right as it all happened so suddenly; I did not know my black moor was full of eggs until the males started chasing her around.
I am emailing you because I would like to get YOUR opinion on fry food, and also on where I should raise them.
<The "where" is easy, a 10+ gallon aquarium away from the adults. Juvenile fish are very sensitive to nitrate and the other chemicals that build up in busy tanks, and frequent small water changes are crucial to long term success. This is doubly true for eggs, which get fungused very quickly if water movement isn't sufficient. Old school aquarists used Methylene Blue (at about half the dose instructed on the packaging for treating sick fish) together with an airstone placed nearby the eggs to keep oxygenated water moving.>
I have been doing a lot of research over the past few days into fry care, but have found a wide variety of opinions as usual, and you guys have not led me astray in the past. I could keep them in the mesh breeder in the 50 gal (if you recommend this option, for how long?),
<Would not, unless you're doing this just for fun and don't mind the majority of eggs and fry dying, as you'd likely end up with just one or two fry a half inch or so long after 4-6 weeks.>
or I could put them in a 6 in. high, 20 gal tank by themselves.
<A better choice if you want to rear a sizeable batch of fry.>
Water quality and filtration are excellent in all tanks, and all have been cycled. With regard to food, I found several websites recommending to hard-boil an egg and mash it up in the tank water; is this sound advice?
<It can work, but more because the egg yolk promotes growth of infusoria, and that's what the fry end up eating for the most part.>
Or is there something better you recommend?
<By default, a decent liquid of powdered fry food will be adequate for a non-serious approach to rearing Goldfish fry; something like Liquifry for egg-layers or Hikari First Bites.>
Would you recommend the Hikari frozen Spirulina/brine shrimp once they reach a certain level of maturity?
<Certainly worth trying if you have these foods and use them anyway. Try a little and see what happens. Unlikely to be much use for fry under an inch long though. Not a replacement for newly-hatched brine shrimp!>
If so, how old should they be? Should I float aquatic plants for them to nibble the algae off of?
<Java Moss is great for this, but an air-powered sponge filter is just as good.>
And finally, if any fish are born with severe deformities, would you suggest freezing those fish as a method of euthanasia (I am emotionally dreading this part, but if I have to do it ...)?
<I prefer Clove Oil, 30 drops to a litre will make a safe, painless killing bath. On the whole vets don't recommend the use of iced water for killing fish. Do read elsewhere on WWM re: euthanasia.>
Thank you very much for your help in advance!
<Good luck, Neale.>
RE: Goldfish laid eggs in aquarium; want to ensure best care for fry    9/18/13

Thank you Neale! You guys are so very helpful.
<Most welcome, Neale.>

Fish eggs     5/13/13
I just returned home to find hundreds of eggs in my black moor's tank. There have adhered to everything and are all through the substrate! They are not fertilized and I need to get them out before they rot. Is there an easy way to do this? Do I need to add a bit of salt or anything to the tank?
Thank you:
<This can be trouble for the livestock... I'd remove them to elsewhere pronto, and dump the tank out completely... rinse the gravel, scrub the sides down... Granular salt can be use on glass tanks... Bob Fenner>
Re: Fish eggs     5/13/13

Thanks, Bob-
I got them all out but that was NOT fun- those eggs are stuck like glue. I hope this doesn't happen often!
<Ah yes... a mess; that with decomposition can really be trouble. B>

Re: Goldfish might be egg bound   6/11/12
Just as a follow up on the Oranda, she has passed. She put up a good fight but as she tried to swim she was bumping her wen on the bottom of the aquarium and developed irritation that kept worsening.  Seeing her suffer was too much so I put her down gently. I hope to never go through that again.
<Thank you for this follow up. BobF>

Immaculate Conception in Goldfish      6/1/12
I have a question that I cannot seem to find an answer for despite extensive searching of your forums in addition to Google web searches.
Can a juvenile Common Goldfish survive for months living in the canister part of a canister filter???
<Mmm, likely so; yes>
Let me explain...
I have a 55 gallon bow front tank that houses 6 Goldfish (1 Common, 1 Comet, 1 Shubunkin, 1 Pearlscale, 1 Oranda & 1 Black Moor) and 2 Gold Dojo Loaches.  (*Note: I realize this is too many Goldfish for this size tank but I'm in the process of setting up a 700+ gallon pond outside and the Common, Comet & Shubunkin will be moving out in a month or so.)
<Ah good>
  Late last year I did a complete overhaul of this tank, which included the addition of a canister filter for more efficient filtration of the Goldfish waste.
<Also good>
 Everything has been great since the overhaul and all of my fish have been happy and healthy in their new, cleaner, environment.  I admit I was negligent  in remembering to clean the canister filter and it had been over two months since I had last cleaned it.
Last weekend I unhooked the canister to clean it, and the associated hoses.
 I pulled the media basket out of the canister and was preparing to dump the dirty water in the sink when I noticed a movement in the canister. 
Further investigation revealed a small, approx. 1 inch long, juvenile
Common Goldfish!?
At first I was horrified that this poor fish had been living in the canister filter, then I was perplexed as to how such a small fish got into my tank and subsequently into the canister filter.  I've never had a fish that small.  My Common and Comet were "carnival" fish that I've had for over 2 years and they have grown from a couple of inches to approx. 6 inches each now.  All of the others were added last year and they were all large enough to avoid being picked on by the large Common and Comet.
So then I start thinking that maybe the juvenile is the result of a fertilized egg that was sucked into the filtration system and somehow managed to survive by feeding off of the food particles and algae that was brought into the filter (that was well overdue for a cleaning).    I
started researching this possibility online and everything I've read says:
1) Goldfish DO NOT breed in captivity and 2) Goldfish fry need a very clean environment to survive.
<Mmm, I disagree. They DO definitely breed in captivity... and often in less than ideal water quality>

I'm not hallucinating...I have the picture to prove it...Have you ever experienced anything like this? 
<Not a goldfish in a canister, but many other species, yes>
Although Goldfish are not supposed to breed in captivity, my Common Goldfish swells up a couple times of year and the other fish chase her around relentlessly.  Not being familiar with Goldfish breeding, I just assumed the swelling was a tumor or constipation and the other fish was chasing her sensing her weakened state (although she was acting and eating normally during these times).  The Common's swelling is asymmetrical, more on the left side of it's body.  The swelling disappeared after approx. 3 weeks and I was glad the fish wasn't sick but I never did figure out why the swelling had occurred in the first place.  I noticed last week that the Common is swelling up again on it's left side  but there is no chasing behavior from the other fish yet.  The Common is approx. 6 inches in length.
So... the only conclusion I have come to is either a Goldfish defied the rules and spawned or this juvenile Goldfish is the product of Immaculate Conception.  :)
<Mmm, not so immaculate>
The juvenile is very active and aside from red, irritated-looking gills, eating well and thriving.  I moved it into it's own 5 gallon tank where it's zooming around, happy to be free from the confines of the canister filter.
<Appears very healthy>
I've attached a couple photos of the juvenile and another photo of the Common Goldfish (foreground of photo) that has exhibited spawning behavior in the past.
Thank you,
Sara M.
<Thank you for sharing. Bob Fenner>

Re: Immaculate Conception in Goldfish     6/1/12
Thank you, Bob, for confirming that I'm not crazy!  Will make sure I clean the canister filter regularly now and stay on the lookout for more "surprises" since I obviously have at least one frisky female (and male) in the tank. 
Thank you,
Sara M.
<Welcome Sara. BobF>

Goldfish fry & dominance or bullying issue... repro. f'    3/15/12
Hi I hope you can assist me I did search and read a lot of the postings but did not see this particular issue addressed. A brief explanation of my aquarium set up and situation. We had 2 common goldfish & 2 comets in a pond and when winter came rescued them brought them inside put them in a 10 gallon tank -
<Much too small>
 I know too small - we then added 2 fan tail goldfish about 6 months later - they all survived reasonably well in this situation with a basic waterfall filter.
<Mmm, no... metabolite build up, exposure... is damaging>
 We had intentions of re-introducing them to the pond this past summer but became worried about birds eating them and other factors. We then purchased a 90 gallon tank moved the 2 commons & 2 comets over to my boyfriend's condo and left the 2 younger smaller fantails in the 10 gallon tank. My home has a water softener
<Get, use the water from "outside"... Goldfish like hard, alkaline water conditions>

that also de-chlorinates and I used Nutrafin Aqua+. He used Stability in the tank for about 8 days prior to moving the fish & misunderstood this to be a de-chlorinator - we were informed by the aquarium store that this was all we would need to treat the water -
<? Maybe... what re cycling the biofilter? Water quality test results?>

they were fine when moved as I assume the chlorine had evaporated during the 8 days. About 4-5 weeks after moving the 4 fish he did a water change treating the water with Stability the 4 fish all perished within 2 hours. It was pretty upsetting. The day before they died he noticed one of the comets chasing the other aggressively (we now understand this to mating behaviour).
<No... too small>

3-4 days after the adults died he was cleaning the tank and discovered that there were fry in the tank.
<? Not goldfish>
 There were probably 50 or so but through ignorance and misinformation we did not properly get the pump intakes covered in enough time or realize we needed to remove the fry from the large tank. By the time we did remove them we had 4 fry - we moved  them to my 10 gallon tank and filled it only half full and are using a sponge filter. We then move the two fantails to the 90 gallon tank and they are happy.
Anyhow it is quite miraculous that the goldfish fry survived and we feel very guilty and sad about the adults dying - although they would have likely eaten all the eggs and the fry. We are trying to do everything to properly care for and keep the babies alive. One did perish after about 2 weeks - 3 are alive and now about 6 weeks old. I am operating a clean tank with no media on the bottom and no plants, sponge filter & am changing 25% water and siphoning out any uneaten food daily. I treat the water with Prime & Stability. I was feeding them 3-6 times daily mashed up in tank water Spirulina which I aspirate into the tank with a syringe, I alternated in the past month with crushed up flakes also aspirated into the tank. They seem to eat and like both equally. I have a test kit and all of my chemical levels are exactly in line.
The problem. About a week ago I noticed that one of the fry seemed to have tripled in size almost overnight. 2 had been about the same size initially with the third a lot smaller - now I seemed to have one that was twice as long and 3x as wide as the other two. The two smaller ones started acting strangely zipping along the surface like they were on scooters or something - dashing and darting along crazily sometimes even colliding. This went on for a few days and I noticed that they were staying mostly near the surface or an inch or so below the surface. This behaviour got worse and they seemed to be staying only on the top of the water at the edges of the tank. I spoke with the aquarium store and they told me it was likely a dominance issue
<? Doubtful>
within the tank and that I needed to separate the larger fry from the other two with a screen. I went out and bought the screen separating them and paying closer attention to the smaller fry behavior & thought they were also having swim bladder problems as they were now not venturing off the surface and sticking to sides of tank and lying on their sides at times. This had occurred before with one of our fantails so I knew that feeding them peas could work. Hard to do when the peas sink and the fry are staying at surface. I read online that using a toothpick might work - well for about 3 times over the next day I chased them around their space with a pea on a toothpick I did see them eat it on occasion - the rest of the time they seemed to think I was chasing them with a big green bat and kept trying to escape it. The aquarium store said that if it was a dominance issue the fry may be too frightened to go down to the bottom of the tank to eat and it might take a couple of days before they will realize it is safe to do so.
In the meantime I thought if it was a swim bladder issue they might die first.
Since I both separated them and started feeding them peas at the same time I do not really know what the issue was. After one day they were able to swim down further and I definitely saw they had a buoyancy issue as they would swim part way down and then bob back up like a balloon and could not stay down. By the end of about 24 hours they were able to go to the bottom of the tank and they ate voraciously for about 3-4 hours bobbing up and down on their noses like they were pogo sticks. They have plumped out again and regained their normal vigor and are eating and swimming fine. So now I don't know what to do about removing the divider and putting all 3 back together again
<Should be fine>
 I can't find anything about this anywhere. The larger one is still at least double the size of each of the smaller ones. I know that goldfish are supposed to be social and I do think that Big is feeling ostracized and lonely. He faces the wall most of the time like a bad kid sent to sit in the corner of the classroom.
So here comes the rest of my ignorance. Would the smaller fry have been scared by the larger one that they did not eat and became weak and would this somehow have created the swim bladder problem - due to not eating or staying on the surface?
<Not likely an issue period>
 I know it says to reintroduce them to each other when the smaller ones catch up - however it seems to me that they are so much smaller that they are not going to be the same size. If I put them back together how will they fare? I guess also did they just have a swim bladder problem? Or a combination of dominance and swim bladder.. Thanks for your assistance! Rhonda
<... Again, not likely goldfish young... but some other "contaminant"...
Goldfish won't live, be large enough in a ten gallon to reproduce...
Dominance amongst young fishes when very small? Not likely. Bob Fenner>
Re: Goldfish fry & dominance or bullying issue   3/15/12

Thanks Bob for your help. Do you know what the odd zipping around on the surface behaviour was?
<Mmm, could be due to stray electrical potential, water quality, just normal behavior...>
 Just to clarify too that the fry are definitely goldfish as no other types of fish in the tank,
<Strange though... I'll try to be clear/er here: Potentially reproductive size goldfish really can't live any time in such a small (10 gal.) volume.
Perhaps they (whatever they are) "came in" w/ the goldfish>

nor was anything added or moved from anywhere that could have introduced eggs. It is really confusing when the aquarium stores and much online information seems so contradictory all of the time.
<... the Net is a mix of useful to not input. WWM is more consistent, accurate>

I am going to take the divider down so that the 3 fry are together and will try to address the water softener issue. I believe that all of my indoor taps are softened and I live in Northern Canada so my outdoor taps which are not softened water cannot be turned on in the winter without a plumbing rupture in the line. Any other suggestions on this?
<Haul someone else's water for use here. Read: http://www.wetwebmedia.com/FWSubWebIndex/GldfshH2OF.htm
and the linked files above; or just search on WWM re soft/ened water use>
 Do I re-treat the water somehow? I am not sure if these fry are comets or commons
- as we had 2 adults of each in the 90 gallon tank. I know that they cannot stay in the 10 gallon tank as they mature - how long can they stay in 10 gallon tank - the largest including tail is about half an inch long the other 2 are smaller.
<Keep reading>
We are trying to figure out what to do with dividing the fish up - in the 90 gallon tank we have two fish right now - Tuna we think is a fantail - and Waggles a calico fantail or veiltail - I find the online photos hard to determine. If these 3 fry are commons or particularly comets they are best not to go in with the fancy goldfish? My boyfriend wanted to buy two Bristol Shubunkins as he liked the way they look and put them in with the fancy goldfish. I read on your site that Shubunkins body type is considered to be like a comet and that they are boisterous and not good with the fancy goldfish - but I also saw other information that said they are fine together. Could there be a difference between the more common London variety vs. the Bristol in terms of its compatibility?
<Not likely; though fancier varieties of goldfish may not be able to compete>
Maybe a better alternative is to put in the 90 gallon tank 2 Bristol Shubunkins, and these 3 goldfish fry - which are either commons or comets -
when these fry are large enough of course. Then I could move the two fancy fish to a 2O gallon tank and keep the 10 gallon tank as an emergency tank.
Thanks for your help. Rhonda
<Welcome. BobF>

Goldfish might be egg bound   8/28/11
Hi WWM crew, I would like to extend a big thank you for the work you do. I have learned so much from your site since discovering it early this summer.
<Ah, good>
I have found answers to most of my fish questions just from browsing the site. This time I'm not as clear on what is happening to my goldfish.
So starting out I have three goldfish, two (fan tails sold as Ryukins, but lacking full shape) are showing breeding stars and chasing the Oranda.
This chasing has gone on quite a bit over the last month.
<I hope you...>
She seems bent as if they bullied her into the wall too roughly.
<... separated the female>
She has a visible opening at her vent where the eggs seemed trapped. I would like advise on whether she should be isolated
<Should have been, and should be now>
or should they be allowed to help her along. I have read stories of stripping the eggs, but I do not want to hurt her. If there are any steps I can take to aid her please let me know.
<Better for now to (time gone by) to allow the eggs either to pass or be resorbed. Please read Neale's pc. here re the use of Epsom:
and the related linked FAQs file above. Bob Fenner>
Re: Goldfish might be egg bound   8/29/11

Thank you for your quick response, I'm moving her into a ten gallon quarantine. I'll be adding a spoon of Epsom salt, and will keep you posted on her status. Thank you so much!
<Welcome! Do monitor (daily) water quality (ammonia, nitrite...) and have water ready (from the main tank is best) for change outs. BobF>
Re: Goldfish might be egg bound   8/29/11
I am happy to report improved behavior from the Oranda.
She is much more active and is no longer hiding in the corner. I am also considering one reasons for her discomfort may have been constipation.
Seeing that she has become a living Play Doh factory(I remember using flakes and granules earlier this summer when I first brought her home) she is now on mashed pea and veggie diet, and has been for a while. She is still slightly bent, but has improved so I am hopeful she may completely recover. I would also like to know how long she should remain in the Epsom bath?
<If not too concentrated, for weeks>
Thank you for your help.
<Certainly welcome. BobF>

Help please! beh., repro.  -- 06/26/11
Hello W.W.M crew. Well to cut to the chase, I am the proud owner of two goldfish both roughly three years old. One is a comet (gender unknown) called Jaws, the other is male Lionhead cross (I think) and he has like a white pimple on the top of his head not on his gill coverings.
<These do occur from time to time, and can be readily distinguished from spawning tubercles because those tubercles occur in matched pairs on either side of the head. A single pimple is exactly what it appears to be, and should be treated primarily by optimising water quality but also by using an anti-Finrot medication to kill off any external bacteria.>
Over in NZ it is winter and isn't goldfish breeding season in summer/spring?
<Correct, they get frisky when the water gets warm.>
because I have been researching goldfish breeding and it said that they "chase" each other and well they have been doing that ever since I bought Rocky.
<They also chase when being aggressive. Goldfish are social, and in small groups, i.e., less than, say, three specimens, it's possible for a dominant male to be aggressive towards a second male or a female kept with him. In bigger groups this hierarchical behaviour is more spread out, so no one fish gets bullied all the time.>
Anyway they have never previously bred before and I'm not even sure the gender of my comet and a breeder told me they might breed so my questions are... 1. How can I sex my comet?
<Sexing Goldfish outside of spawning time is hard, as the key features are the spawning tubercles on the head of the males. But as is often the case with Cyprinid fishes, males tend to be more aggressive, and females tend to be plumper around the abdomen, particularly as spawning season approaches.>
2. If my comet was female would they successfully breed?
<In aquaria it's actually very difficult to breed Goldfish. When spawning Goldfish swim very rapidly around the pond or canal they inhabit, and they lay their eggs among floating plants. While it can be done in an aquarium, it is very difficult. You need a few pots of feathery plants (for example Elodea, Cabomba or Myriophyllum), a sufficiently large tank (50+ gallons), and a heater to keep the temperature at a steady 18 C. Pairs are introduced to this spawning tank, ideally with a tank divider initially (egg-crate is ideal) so that the female can be fattened up and the male can watch her longingly! Small live foods such as daphnia and bloodworms, or their wet-frozen equivalents, are extremely useful "conditioning" foods that mimic the abundance of prey available in springtime. Usually breeders take out 20-25% of the water, replace with cool water to mimic rainfall, remove the divider (if used), and then hope for the best! Eggs are scattered among the plants, and then the adults must be removed. The fry are not difficult to rear, but they are small, and will need 4-5 meals per day of things like liquid fry food and brine shrimp nauplii.>
3.If they aren't breeding what is the white pimple on Rocky's head?
<See above.>
4. If my comet is female how could I increase breeding success?, e.g. hand breeding or other methods?
<Do try and get a copy of a book like 'Fish Breeding' by Chris Andrew, a cheap and easy to follow guide to breeding Goldfish and lots of other pet fish species. Second-hand copies can be picked up for pennies.>
Thank you
Sincerely Eden 14 NZ
<Good luck, Neale.>

Can You Breed Goldfish In One Tank?  11/18/09
My tank setup currently is as follows:
gallons- 50 gal.
dimensions- 18"wx18"Hx36"L
hard water (high mineral content)
ph 7.5 to 8
2 40 gal. in tank filters
2 4" sintered airstones
1 bubble wand
several fake plants
no gravel or real plants (for easier cleaning)
no added salt
chemicals used in water changes- ammonia, chlorine, chloramines, nitrate, nitrate, heavy metal remover (Amquel + and Stresscoat, sometimes Prime brands used), and a phosphate reducing bio extract (AquaSafe brand). I used mixed amounts of these chemicals. Usually splitting the dosage to 25 gal.
rather than treatment for a full 50 gall on each chemical. I do this to reduce stress on the fish and avoid putting too much of a chemical in the tank). I do this when I use more than 1 chemical at a time. When I use only 1 chemical at a time, I use the normal recommended dosage. Except for the bio extract. That does not do the same thing as Amquel, Stresscoat, or Prime. So I just use 1 ml per galloon during water changes with the bio extract. This usually amounts to no more than 6 to 8 ml. during water changes. Not a lot compared to what Amquel (25 ml to 50 ml.), Stresscoat+ (25 to 50 ml.), and Prime (5 ml per 50 gal. or 2.5 ml for 25 gal.) recommend for the tank size I have (except the Prime, which I tend to use by itself). So chemical interaction should not be an issue with my tank.
current # of fish in tank- 3 adult goldfish all roughly 1 yr. old (1 male American common fantail, 1 female American common fantail, 1 Ryukin female (she is the largest of my fish)).
future fish I would like to add to the tank- 1 adult male common American fantail (I have him currently in a 10 gal. tank by himself) and maybe 1 goldfish I bred and raised.
food- Spirulina flakes, goldfish flakes, occasional peas, free dried bloodworms, free dried green or brown seaweed, and freeze dried brine shrimp. Occasional vitamin c supplement and garlic guard. Maybe fresh, whole orange pieces (no skin or bitter white stuff attached) or blanched lettuce once in a while.
<All sounds fine.>
My question:
If I have 3 to 4 adults in a 50 gal. tank (two common American fantail males, 1 American fantail female, and 1 Ryukin female) can I breed and raise fry in the same tank as the adults? Can I use a tank divider to breed the adults and raise the fry, while keeping the fry separate from the adults until they are old enough to be placed with the adults? How many goldfish can live comfortably in my 50 gal. tank? Is 5 too many to keep in a 50 gal. tank?
<No, you should be okay with that. Depends on the varieties of course, and Standards, Comets and Shubunkins do need as much space as you can give them, since they get big and like to swim around a lot. But Fancy varieties are smaller (to 20 cm/8 inches) and don't move about so much. Five in 50 gallons should be fine, provided you have a good, strong filter.>
Also did you know they do not recommend keeping platys and goldfish together in the same tank because of the goldfish's tendency to produce large amounts of Ammonia?
<This isn't true. Goldfish produce no more ammonia than any other cyprinid of similar size like, say, a Tinfoil Barb.>
Thus this could wind up killing the platys.
<Yes, Platies are sensitive to ammonia, perhaps more so than Goldfish.>
Just an interesting little tidbit of information I thought perhaps you would find useful.
<It's not really true though. Provided the aquarium has adequate filtration, you can keep Goldfish perfectly well with subtropical fish such as Platies and Peppered Corydoras (assuming of course you're providing a comfortable water temperature for all the fish being kept). But most people who keep Goldfish don't provide adequate filtration, which is one reason so many Goldfish get sick and die prematurely. Since Goldfish are a bit tougher than Platies, Platies will succumb to poor water conditions before the Goldfish.>
I found this out the hard way. I lost many platys and one goldfish before I learned what I had done wrong. Poor fish. This rule also seems to apply for swordtails, guppies, and other small tropical fish.
<It's honestly not a rule.>
I have no idea about larger tropicals and goldfish. But that is because I do not want large tropicals. (Though some species can be quite beautiful).
For instance, I heard rumors that cichlids and goldfish can be put together.
<Yes, they can, but again, this assumes all other factors are equivalent.
Cichlids generally need much warmer water than Goldfish, but there are some subtropical species like Port Acara that can be kept with Goldfish in sufficiently large, well maintained tanks. A Goldfish is really not much different to any other large cyprinid like a Tinfoil Barb. It isn't any more messy than any other herbivorous fish of the same size, such as a Plec, and perhaps rather less so than equivalently sized carnivorous fish like Oscars.>
Yet I have no desire to try this theory out. The only fish over 2 or 3 in.
I want are my goldfish. And cichlids get quite large.
<Not all of them. There are many very small cichlids, including some small enough to live in snail shells.>
Anyway, thank you for your time and answers. They are most appreciated.
<Glad to help. Cheers, Neale.>

Weird Microscopic Creatures In My Tank  10/27/09
I have found some odd looking creatures in a small, 3 gallon tank I have been using lately. I have been trying to hatch goldfish eggs in this small tank with no success. 3 times so far. I have a sponge bubbler in the 3 gallon tank. The bubbler seems to work in the tank. But I have not seen the goldfish fry.
<You will need more than three gallons, to be honest. Fish eggs are very sensitive to poor water quality. What happens is that still water and a build up of organic material promotes the growth of fungi and bacteria.
These in turn go on to eat the eggs, and up to the point where the fry become actively swimming, the fry can be infected too. I use an 8 gallon tank for rearing eggs, and even that tank can sometimes get dirty so fast eggs become fungused.>
Yet they are very tiny I hear (about the width of a human eyelash I heard one site say).
<That's a bit of an overstatement. Goldfish fry are smaller than, say, a newborn guppy, but comparable to newly hatched Corydoras or Danios.>
So about two or three days after the eggs have been laid I have tried to put very finely ground foods and live brine shrimp eggs in for the fry.
<Almost never a good idea to add food before you see fry swimming about.
Firstly, the newly hatched fry won't be eating for the first two days.
During that period you will see them sitting on the bottom flicking their tails but otherwise not moving much. They are using up their yolk sac.
Adding food will only be a waste, and potentially ruins water quality at this key stage.>
Included in the powdered foods are ground up bloodworms and regular goldfish flakes ground up fine and Spirulina.
<Likely too coarse for newborn Goldfish, which really do need infusoria ("green water") and/or liquid fry foods. It'll take a week or so after their first meals before they can tackle finely powdered flake and brine shrimp nauplii.>
I also include liquid food and a little artificial rotifer, which I was told is good for baby fish and brine shrimp. After about a day or two I still do not see any goldfish fry, but I do see transparent creatures hanging around the bottom of the tank. They are translucent gray to completely clear in color. They have two large dots for eyes that are usually red, but have also been black. Then they will develop long bodies with eyes placed on their heads like those of a hammer head shark.
<Could possibly be goldfish fry. Very young fish are usually obviously different from the most likely other things that might be in the tank: nematodes, flatworms, or copepods.>
It also appears some of the creatures have heads similar to those found on a mature adult dragonfly.
<Juvenile dragonflies and juvenile damselflies (these latter smaller and have three "tails") are common in aquaria sometimes, usually coming in with plants or live food. They can, will eat fish fry. They are obviously insects though, i.e., they have compound eyes and six legs.>
There is no salt in this freshwater tank system. But our water does have a high natural mineral content. My question is are these odd creatures brine shrimp nauplii?
Or could they be bloodworm larva regenerating? Can bloodworm larva pieces and fragments do that if they are not cleaned up?
Could they also be flatworms?
<Potentially, yes; these look like flat slivers that slide along the glass and over gravel. Often brown or pink; may have two eyespots at the front end.>
And do brine shrimp (at any stage in life), bloodworm larva, and flatworms eat small things like recently hatched goldfish fry?
<No, no, and yes.>
Below I have tried to include a rough outline of some of the critters I have found in my tank. What do you think they are? And would they eat the tiny goldfish fry and eggs?

| | |
/ \

1. . . 2. . . 3. (' ') 5. ( ( ) ) 6. /\/\
| \/ | |
# 5 is the creature with the bug head I mentioned, #2 is the one with the shark head I mentioned (though in this outline it does not show the classic T shape this creature usually shows, though it does sometimes show the shown v-shape too). None of them appeared to have an outer shell like a fish louse would have. So I do not think they are fish lice (though I could be wrong). Sorry I could not provide a proper picture, as I threw out the water in the 3 gallon tank already (all 3 times).
<Sorry, these diagrams don't mean anything to me.>
I would just really like to know what these creatures are, so I can identify them better in the future.
<Do look out for an excellent little book called "Fish Breeding" by Chris Andrews; it's easy to buy online, often inexpensively, and well worth having. It includes details on breeding Goldfish as well as numerous other freshwater species.>
I hope these rough outlines and the descriptions above help. Thank you for your time.
<Cheers, Neale.>

Asexual reproduction in comets -- 10/22/09
I have a tub garden 2x2x2 with a variety of plants and one comet. I have had it for 4 years, the water remains very clear (the top two inches freezes in the winter) and the comet appears very healthy (dark orange gold). I do not give supplemental food, just the plants and bugs. The top freezes in the winter. Yesterday I was adding water and saw two small comets??? How could this be? The original is solid gold. One little one is gold with a white spot on its underside coming up the sides and the other is pale golden tan with black fins.
Thank you,
<Hello Kim. Goldfish are not parthenogenic, and so wherever the new fish came from, it wasn't from a *single* Goldfish. There are three explanations. The first is someone added some more fish, deliberately (i.e., as a "surprise") or accidentally (e.g., some fertilised eggs alongside a new aquatic plant). The second is that there was more than one Goldfish in there all along. Finally, there's the idea often mentioned of fish eggs get transported from pond to pond on ducks' feet. Whether this actually happens is up for debate, but it's often suggested. Hope this helps, Neale.>

Re: Asexual reproduction in comets -- 10/22/09
You answered it, I also have a pond with comets and they reproduced. I move plants from the tub to the pond and from the pond to the tub. I did that this spring, must have transported fertilized eggs on a plant.
Thank you
<Glad to be of help. Cheers, Neale.> 

What kind of Goldfish? Crosses   8/8/09
I bought 2 dozen 1 inch "feeders" several months ago to stock my economy 125 gallon preformed Lowe's garden pond. A month ago I tired of cleaning it out and changing the water every few days so I dug a larger 350 gallon pond closer to the house and used a liner. I moved all of the "feeders" plus I bought 4 itty bitty Shubunkins and the larger ones that were on sale for $1.99 ea. Last week I was told that to 30 or so fish in
my 350 gallon pond were overcrowded and I needed to cut the population in half.
<Mmm, not for a few years, really>
The water does get ugly pretty fast despite the 40 Large Trap Door Snails, the Water Lettuce and the other plants I have added. The $100 dollar filter in the bottom of the pond doesn't seem to help that much either.
<There are a few things one might do here... Read:
and the linked files above>
I don't know if I feed to much or what (twice a day) at any rate I have started culling and have pulled these out and put them in a 20 gallon tank till I can find them a home. My question is, what are they?
<Goldfish... akin to domestic dogs, all goldfish are the same species (actually dihybrid cross)... and mix genetically... these are comet X Shubunkins>
1 of them looks like it might be a common but I'm not sure about anything, Do Comets have tails this big and a couple of them have little bumps on their faces, what's that?
<Yes and likely prenuptial tubercles... see WWM re>
Any info would be gratefully appreciated.
<Enjoy the learning. Bob Fenner>

Bubble eyed goldfish having babies? 8/6/09
I've read several of your articles and have not found an answer to our strange situation. We've had our bubble eyed goldfish (I'm assuming this is the correct name) for several months. Several different types of fish accompany it in our 55 gal. tank.
<What other kinds of fish?>
Around July 10th, we noticed a new goldfish...looks like a baby. 2 days ago we noticed another little baby goldfish...they both look exactly like their "momma". Since this was the only goldfish in the tank, what did she breed with and should we be expect more at any given time? And I don't see any eggs...I read that they only lay eggs and don't have live birth...so I'm really curious what's happening here! Thank you so much for your time!
<Doubt these are baby Goldfish. For a start, no, Goldfish aren't livebearers. And no, they don't often lay eggs in aquaria for reasons we don't need to go into here. But if the other fish are, for example, Platies, Guppies, or Swordtails, then those might have produce some baby fish, and that's what you're seeing. Cheers, Neale.>

Pregnant Fishy 05/27/09
What does a goldfish look like when it's pregnant? And will fish eat their own babies? If u answer my question, please mail the answer back 2 me. My E-Mail is sp.wishes@yahoo.ca.
<Please read here:
Sara M.>

Determining the sex of Red Oranda Goldfish  11/19/08 Good Evening, We bought a goldfish about three months ago for our son for his birthday, and got one of those starter kits that were suggested at the pet store. It is of 2.65 gallons (it is cleaned every day with 25% water change with the vacuuming of the gravel) and after going through yours and similar websites realized that it was a wrong decision (our stupidity didn't do research before jumping in head first), and now getting a bigger tank of about 29 gallons and were thinking of adding one more goldfish to the tank. <Well done! A 29-gallon tank will be just right for two or three happy, healthy Goldfish!> Would like to know how to determine the sex of the goldfish? Is it even possible to determine it? He/she is about two inches long and is a Red Cap Oranda. Earlier when we got her he/she passed out poo that was transparent and stringy and covered with the bubbles, on different websites it was stated that can be a sign of eggs being absorbed in the female goldfish body. Is that correct, then our goldfish is a female. <You can't sex Goldfish when they're young. Once mature (i.e., upwards of 15 cm/6 inches in length) males have distinctive tubercles on the head. They come and go depending on whether the male is in the breeding season. So usually you see them in spring. Anyway, they look like white spots on the face, but unlike a disease, the spots on the left and right side of the face match. Apart from this feature, Goldfish are essentially unsexable.> Of all the websites your is one of the most informative. I didn't find the answer to my questions by doing the search I am sitting here and reading your websites since morning. I am sorry if you had to answer this question again. Thank you very much and you have an amazing website. Do read this article: http://www.wetwebmedia.com/FWsubwebindex/gldfshmalnut.htm Usually when Goldfish have odd-looking faeces, it's because of a lack of fibre in the diet. You see, the worst diet for a goldfish is flake and pellets, day-in, day-out. Much better is a diet with lots of green foods or cheap aquarium plants!> Regards, Midhat <Glad to help, and thanks for the kind words. Cheers, Neale.>

Goldfish reproduction  9/29/08
We were given fish some months ago for our very large garden pond and a white one was obviously heavily 'pregnant'. She has become huge now and quite lop sided. Is this normal and how long before she deposits her eggs. Also could she become 'egg bound' and if so what should we do.
Many thanks
<Hello Roberta. Goldfish can become swollen for all kinds of reasons besides being "ripe" with eggs. Indeed, if these fish are outdoors and it isn't springtime, it's unlikely these fish are preparing to spawn. For the most part, Goldfish breed in ponds without any effort on the part of the aquarist. The males will become rowdy and develop white "spots" on their heads called breeding tubercles. They will chase the females about, the then eggs will be laid in the plants. The eggs and eventually the fry develop naturally, and at least some will survive. If it isn't springtime in your part of the world and you have one fish looking distinctly swollen, do consider the other factors. In particular, review diet. Surprisingly to some, Goldfish Food is about the worst thing to give Goldfish in the long term.
In ponds, a combination of algae and aquatic plants is really all you need provide them, and only occasionally supplement these with high protein foods. Goldfish are herbivores, so giving them the same protein-based foods as give carnivorous tropical fish is akin to giving dog food to a sheep. Cheers, Neale.>

Re: Goldfish reproduction  9/29/08
Thank you so much for your prompt and informative reply.
Do you think we should take the fish from the pond and have her 'looked at'?
<Hello again. If you're suggesting that you have your fish examined by a vet, then that's never a bad idea. But do telephone your vet first: not all are experienced with fish. Aquarium shops will sometimes look over fish for you, but the quality of any advice you get will vary somewhat, to say the least! In any case, I'd start off by assuming diet is the issue, and act as described in the "Floaty, Bloaty Goldfish" article I linked in my last e-mail. Epsom Salt (magnesium sulphate) costs next to nothing to buy from a chemist (drugstore). Maybe a couple of quid for a kilo. Review diet as well. If these things don't help, then have the fish "looked at"! Cheers, Neale.>

Re: Goldfish reproduction  9/29/08
Thank you so much Neale.
<Happy to help, and hope your fish recovers soon. Cheers, Neale.>

problem with fantail fry - 05/31/08 hi all anyone help fry are 6 weeks old feeding them Liquifry 2 and baby brine shrimp had no problem till now starting to die with what looks like white stringy fungus? coming from gills. can anyone help please before they all die thanks Sean <Hello Sean. If it looks like fungus, chances are it *is* fungus. Fish fry are very prone to fungal and bacterial infections if the water or substrate aren't perfectly clean. Many fish breeders keep their tanks minimally decorated to ensure they're easy to clean, and use anti-fungal medications such as eSHa 2000 even before they see signs of ill health. And no, fish medications shouldn't harm the fry. It's also important to do regular, large water changes: liquid fry foods and brine shrimp nauplii will quickly pollute the aquarium otherwise. While you may have zero nitrite, the fact is that the background decay allows bacteria and fungi to thrive, and it's this that causes problems for the fry. One last thing. Please remember to type your message out with capital letters in the right places next time. It's one of the few things we expect from our correspondents. Cheers, Neale.>

Is it possibly that my fish could breed with themselves?  5/10/08 They are 2 Calico Fantails one is white coloring and one if dark coloring turning orange so can they mate themselves? Thanks, Jesse <Obviously they can't mate with "themselves" any more than any other fish can fertilize itself. But if you're asking can two Calico Fantails breed, then potentially yes. Very unlikely in an aquarium though. Goldfish breeding needs to be done in a pond, typically with several males and females kept together because their spawning behaviour at least is primarily group rather than pair based. Cheers, Neale.>

The Tubercule  5/10/08 Hi I just want to know what the tubercule looks like or I can give a picture if I can take one that is good enough so I want to know what the tubercule looks like and thank you for helping. <If your ADULT male Goldfish are in sexual condition, you can't miss them! They look like Ick/Whitespot on the face. Easy as that. If you can't see them, then your fish either isn't a male, isn't sexually mature, or isn't in breeding condition. Cheers, Neale.>

Calico Fantail Reproduction 05/07/08 How long does it take for a Calico Fantail to reproduce with itself? and how long till the eggs hatch? <Depends on the water temperature. Goldfish are very difficult to breed in indoor aquaria (read: don't bother). In ponds, you basically leave them to it, and by the end of summer you'll have some baby goldfish. For more, see here: http://www.wetwebmedia.com/fwsubwebindex/gldfshreprofaqs.htm Cheers, Neale.>

Calico Fantail Gender 05/07/08 How do I find the tubercule and what does it look like? <Aren't we doing "please" or "thank you" today? In any case, if you can't see the tubercles on your Goldfish, they either aren't sexually mature or aren't males. They're very obvious on sexually mature male fish. Look a bit like white spots, but symmetrically distributed across the face. Cheers, Neale.>

Do goldfish need less food when they are older than 1 year? -05/07/08 Dear WWMC, You have a very informative site - thanks for all the effort that evidently goes into it. It's great to see such a wealth of experience about goldfish in particular. <Thanks for the kind words.> I have a query that I did not find an answer to on the site (though I did find a lot of interesting information): how do goldfish nutritional requirements change with age? <Doesn't change dramatically, though yes, bigger fish eat less food relative to their body size than smaller fish. This is in fact true across the animal kingdom. While elephants eat a lot, in terms of percentage of body weight, that food is much much less than what a mouse eats.> I have 3 fantail goldfish in a 30 gallon tank, along with a couple of Siamese algae eaters and some white cloud minnows. Everyone is peaceful and I never see the goldfish chasing the others, though they are now much larger. The tank is heavily planted, mainly with fast-growing, low-light things. <Hope this tank is warmed somehow: Siamese Algae Eaters (Crossocheilus siamensis) is a tropical fish and needs water at 24-26 C, slightly more than Goldfish like. Not a combination I'd have recommended, though viable.> The goldfish came to me when they were about 1 inch long, about 10 months ago. Two are now 3-4 inches and the third is more like 2-3 inches. The smallest seems to have a deformity in his mouth that stops him from opening it fully, so I think he gets less food than the others, but he is active and seems cheerful, so I leave him be, because I don't think there is anything I can do about his mouth anyway. <Mouth deformities are common in Goldfish, and as you say, they seem to manage.> My goldies get Hikari goldfish pellets and a variety of flake foods (different brands), they get some of the smaller pellets I put in for the white clouds (a community pellet mix), and they also have raw lettuce, duckweed, azolla (these they will eat until it's all gone) and the live plants in the tank. They love hygro, ambulia and similar plants, but they also seem to eat pretty much anything, including anubias, java fern, crypts and other things they are not supposed to like much. One thing they are surprisingly not so keen on is elodea, so lots of that is growing in my tank at the moment. <Perhaps less tasty than the rest of the (excellent) salad bar you're offering them.> I've also fed them sinking algae pellets from time to time, but not often recently, as I think they are getting enough. <Probably enjoyed by the Crossocheilus siamensis.> I have so far always fed my goldfish plenty, up to three times a day. This partly because it amuses them (and me) and partly because I hope that by keeping them well fed they will wreak less destruction on the plants. In the past when they have gotten hungry they have destroyed many plants, so I try to avoid that because I want the plants to keep growing well to beautify the tank and improve the water quality. <Provided there are plants in the tanks, your fish won't go hungry. So perhaps the way to work things is to establish the minimum amount of flake/pellet food needed such that your plants are basically left alone.> Lately, however, I have had trouble controlling the nitrate levels in the water (my target is less than 20ppm, but I have trouble keeping it there). I have been experimenting with feeding the tank less often or less food at a feed. Yesterday I even went an evening without feeding them. To my surprise this morning, there was no great plant destruction. They must have been hungrier than usual, but they hadn't then uprooted everything in sight. This is really unusual, and rather a nice surprise for me, actually. <Temperature is a critical issue I suspect: in warm water, Goldfish metabolism rises, and they become much hungrier. If the tank was allowed to stay cool, around 15-18 C, you couldn't keep the Crossocheilus siamensis of course, but the other fish would be fine and would eat much less food.> Could it be that my goldies are entering a phase where they need less food or are less driven by hunger to explore/destroy everything in the tank? They can't be at their maximum size yet, surely - they have good water quality, good nutrition and an interesting tank, so I expected the larger two to reach 6 inches at least before they stop growing. I am wondering whether maybe the first year or so is a time when goldfish do eat more and get hungrier when they aren't eating. If so, maybe I can look forward to being able to put more interesting plants in the tank and have them survive long enough to get rooted in and start to thrive - that would be nice :) Much as I like elodea, I don't really want the whole tank full of only that. <Goldfish growth rate *is* fastest when they are small, but it otherwise carries on regardless of age, so that the older the Goldfish, the bigger it is. Temperature and diet both feed into this though.> So, can you please tell me, how do goldfish nutritional requirements change in their first couple of years or with their first few inches? (Or maybe the right question is how does goldfish plant destroying change in their first couple of years?) <Essentially this: give them easier alternatives to the live plants. Try Sushi Nori for example, or blanched curly lettuce and see what happens.> Thanks very much, Helen <Good luck, Neale.>

Re: Do goldfish need less food when they are older than 1 year? 05/08/08 Dear Neale, or whoever is reading this one. Thank you very much for your useful information and sensible suggestions. <You're welcome.> Just to remove your worry on a point: I live in a relatively warm climate (Melbourne, Australia) and the tank is heated by the lights and the surrounding air. I only added the crossocheilus siamensis when I realized that the temperature never drops below about 23.5 and is usually slightly higher than that. I have a heater in there, just in case, but I doubt it ever turns on, except possibly in the dead of night in winter. <Ok.> My problem is much more how to keep the tank cool in summer. I start to worry when the water gets near 29 or 30 degrees (this when the outside temperature is 38 or more and we can't keep our unairconditioned flat cooler than about 30), but actually the goldfish seemed fine this summer, despite my worry. I use all the tricks I know: loads of aeration, moving the cover so there is airflow over the top of the water, keeping the lighting period to a minimum and to the cooler times of the day and, when I'm desperate, putting frozen bottles of water into the tank. They survived their first summer just fine, so I'll be less worried next year. <One old trick is to freeze a couple of litre-sized ice cream cartons (or similar) filled with water. Place in the aquarium when it gets very hot. But at some point, a chiller becomes more cost effective. A low-tech solution is an old "mini bar" fridge. Drill a couple of holes in it, and then buy a few metres of aquarium hose. Wind the hose a few times in the fridge, and then place the ends so they poke out the two holes. Connect the hose to the outlet from the canister filter, so that the water is pushed through the coils of hose. In theory, this system can knock a few degrees off the heat. Perhaps not as good as a real chiller, but cheap and cheerful.> Anyway, thanks again for your excellent work! Helen <Good luck, Neale.>

Re: Do goldfish need less food when they are older than 1 year? 05/08/08 Dear Neale, or whoever is reading this one. Thank you very much for your useful information and sensible suggestions. <You're welcome.> Just to remove your worry on a point: I live in a relatively warm climate (Melbourne, Australia) and the tank is heated by the lights and the surrounding air. I only added the crossocheilus siamensis when I realized that the temperature never drops below about 23.5 and is usually slightly higher than that. I have a heater in there, just in case, but I doubt it ever turns on, except possibly in the dead of night in winter. <Ok.> My problem is much more how to keep the tank cool in summer. I start to worry when the water gets near 29 or 30 degrees (this when the outside temperature is 38 or more and we can't keep our unairconditioned flat cooler than about 30), but actually the goldfish seemed fine this summer, despite my worry. I use all the tricks I know: loads of aeration, moving the cover so there is airflow over the top of the water, keeping the lighting period to a minimum and to the cooler times of the day and, when I'm desperate, putting frozen bottles of water into the tank. They survived their first summer just fine, so I'll be less worried next year. <One old trick is to freeze a couple of litre-sized ice cream cartons (or similar) filled with water. Place in the aquarium when it gets very hot. But at some point, a chiller becomes more cost effective. A low-tech solution is an old "mini bar" fridge. Drill a couple of holes in it, and then buy a few metres of aquarium hose. Wind the hose a few times in the fridge, and then place the ends so they poke out the two holes. Connect the hose to the outlet from the canister filter, so that the water is pushed through the coils of hose. In theory, this system can knock a few degrees off the heat. Perhaps not as good as a real chiller, but cheap and cheerful.> Anyway, thanks again for your excellent work! Helen <Good luck, Neale.>

Is my Shubunkin Goldfish Pregnant?    01/13/2008 Hello. I have a 100 gallon tank with 3 goldfish and an algae eater in it. 2 regular Goldfish and a Shubunkin Goldfish. It is January but has been warm here in Arkansas. And I have learned from reading on your site that goldfish spawn in spring. But, I have recently notice that my Shubunkin's sides are bulging. So is it possible that this fish might be carrying eggs? <Possible but unlikely in aquaria.> I really know very little about fish and the breeding process. So, I am hoping that you can help me with this. If it is possible that this is a female carrying eggs what do I do. How do I care for a pregnant goldfish? <Goldfish don't get pregnant, they lay eggs. Spawning is relatively uncommon in aquaria, though possible.> The two regular goldfish chase each other around the tank. They do not bother the Shubunkin. <Hmm... sexually mature (and active) males display characteristic white tubercles on their heads. They WILL chase "ripe" females, and eventually the fish spawn among plants. But if your "fat" Shubunkin is being ignored, that would suggest against her being in breeding condition.> The Shubunkin (the one I think might be carrying eggs) stays to itself. It hides and stays in the corners of the tank until feeding time. Then it comes to the top of the tank to eat but returns to hide after. It seems to be bulging larger on one side than the other, as well. - Thanks for your time and effort in this matter. Brandy Kidd <Most likely constipation; exceeding common with Goldfish because people believe -- wrongly -- they do best fed Goldfish food. Seems crazy, but in fact Goldfish food isn't all that good for them, at least not day in, day out. Just like humans, they need their greens! Do read this excellent article on feeding Goldfish. Try feeding greens-only for a couple weeks, and see what happens. http://www.wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm Cheers, Neale.>

Re: Goldfish behavior...please help. Repro.  1/6/2008 Hi Neale, Thanks for answering so soon. <Not a problem.> Well, my redcap did laid eggs yesterday, and I could see de tubercles from the male fantail. <Hurrah!> I separated the eggs from their parents, and put oxygen in the other tank, but my question is... do I really need to oxygenate the eggs? <Yes; eggs rely on passive diffusion of oxygen since they don't pump water through "gills". If Muhammad can't go to the mountain... Also, the water movement is important as well, otherwise you'll get fungus.> or is it ok with the surface oxygen? and the other one is, at what temperature do I need to have the eggs? <A middling, subtropical temperature is what you're after. 15-20 C will do fine.> By the way I've put some drops of Methylene blue to prevent the unfertilized eggs getting fungus. <Good.> If you have some other tips for the care of the eggs and fry, I would thank you. Thanks. <Start planning on the food NOW! You want to have the things you'll need to hand for when the eggs hatch and the fry become free swimming. Do remember baby fish need to eat often but in small amounts, and water changes are critical during the early stages. 4-6 meals per day, but with water changes of 25% (at least) every day or two is what you're after. Don't keep the eggs in deep water: the baby fish will need to swim to the top to gulp their first air to pump up the swim bladder. So if the water is too deep, they'll not manage this. 10 cm depth is ample. After a few weeks you can gradually raise the water depth. Keep plenty of floating plants in the tank; the fry will seek shade there and will also feed on the algae and infusoria found among the leaves. Cheers, Neale.>

Goldfish behavior...please help  1/5/08 Hi there! <Hello,> I'm not quite a fish brainer, but I've read a little bit about fish and their breeding, specially mine. <Very good.> I have a 42 gallon tank and I have a red cap and an orange fantail. Today my orange fantail began chasing all around the tank my redcap and I supposed well, it's a common behavior and then I looked for the male tubercles but I couldn't see them. So my question is, can the tubercles appear later? or are my 2 fish are males? <The breeding tubercles should be visible on sexually mature males in breeding condition. If you can't see them, then chances are your fish are either females or else aren't in breeding condition.> And, if they lay eggs, when I separate the eggs to another tank to avoid getting ate, do I have to provide more oxygen or with the surface oxygen is OK? <You will likely need to remove the eggs to another tank to prevent them being eaten. It's just not practical in most cases to leave the eggs with the parents. You can certainly try putting the eggs in a floating breeding trap to see what happens before you invest in a 10 or 20 gallon tank just for rearing fry (which is how experienced breeders rear baby fish). This said, Goldfish are notoriously difficult to spawn anywhere other than a pond, where they tend to breed like rabbits. In an aquarium, you need to provide conditioning foods (bloodworms and mosquito larvae for example) and then cool down the water for a few weeks (to simulate winter) and then warm it up again (to simulate spring). Goldfish spawn in the morning, and the tank should receive some early morning sunlight to "trigger" spawning.> Thanks. <You're welcome.> P.S. I don't know exactly how old are my fish cause when I bought them they where a little big, not too much but they weren't fry. And now they are quite big about 8 cm o more I'm not sure <May be a bit small for breeding still. Cheers, Neale.>

Strange offspring... Goldfish?   11/16/07 I bought 5 fantail fish from Wal-Mart a couple of years ago. They spawned and the fry are now full grown. Some of the fry have only one tail (instead of the normal fantail) and one of them is grey, not gold. Are my original 5 fantails part of some other fish species and those genes only showed up in these few fry? Or are my new fish just a little strange? <Are we talking about goldfish here? In any case, it is absolutely normal for "pet" grade fancy ornamental fish to NOT be true breeding. Such fish are produced on farms mostly for people who won't be breeding them. People who want to breed fancy varieties of fish tend to source fish from other breeders so that they know they are getting true breeding stock. In your case, the fantail fish were presumably heterozygous for the fantail condition, with the fantail gene being dominant over the normal tail gene, so that some proportion (around 25%, perhaps) of the offspring were homozygous for the normal tail morphology and the remainder either heterozygous or homozygous for the fantail condition. Cheers, Neale.>

Male Or Female? Goldfish  11/5/07 I have here 2 of my goldfish I bought yesterday, can you identify what are their gender? Thanks! <Mmm, nope... not at this size... There are some physical differences seasonally in mature goldfishes... Please read here: http://wetwebmedia.com/FWSubWebIndex/gldfshreprofaqs.htm re. Bob Fenner>

Goldfish fry -- 07/23/07 Hi there, <Hello.> Thank you for maintaining such a very informative site and providing us very useful advice. <Cool.> After reading your discussions about goldfish bladder problem, I changed the diet of my fish and witnessed the immediate recovery of one of my Orandas after feeding her some rice (she was at the brink of flipping over). <Very good.> Anyway, my question is about goldfish fry. My Orandas spawned last year and we lost a lot of fries in the third week. According to some Chinese books, goldfish fries die in great numbers when they enter a period when their abdomen split open exposing their internal organs--that is why they are so vulnerable in this period-- and their tails start to fork. <Never heard of this. There's no logical reason why development of the tail should cause the abdomen to split open. But it's a fair point that many fancy goldfish have very bad genes in terms of developmental biology. After all, the "fancy" aspects of these breeds are really mutations, and invariably deleterious ones at that. While ordinary goldfish can establish themselves as feral populations quite easily (they have done so in Australia, for example) fancy goldfish don't because they are genetically poor stock. So it might well be that along with the fancy tails there are some other bad genes that cause problems with other aspects. If there is, there's nothing you can do about it. All this said, breeding fancy goldfish clearly isn't that difficult, given how cheaply its accomplished by fish farmers supplying the ornamental fish industry.> However, I could not find such information published in English. <Over here in England, goldfish breeding is almost always done in ponds where the aquarist has no involvement beyond keeping the pond healthy. There's not much written about breeding them in the aquarium. There are also a lot of myths in the aquarium hobby. Old ones in the Occidental side of things include adding salt to freshwater tanks and the virtues of "old" water. Perhaps the splitting open of the abdomen is a myth from Oriental fishkeeping? It's, what, a 500 year old hobby in China, so certainly plenty of time to accrue its own myths.> Do you guys know anything about this? <Sorry, no. I'd treat the whole idea skeptically for now. See how your batch of fry develop. Other than bad genes, there's nothing about fish that causes their abdomens to open, so you can't do much either way what watch and wait. Keep water quality good, of course, and supply plenty of food. All the usual fish breeding stuff, really.> Thank you very much, Fred <Cheers, Neale>

Fantails-unusual breeding?  6/9/07 Hello, <Hello.> I have looked through a lot of articles on the web but I still can't work out if my fish are ill or just weird. I have three fantails and one black moor that I have had for just a year now and for the first time they are showing signs of being sexually interested in each other. <Why not? They're all the same species... Carassius auratus.> From looking for tubercules on the fins/gill area I think I have 3 males and 1 female. The suspected female however has been the one chasing a small male (although at times they all seem to be chasing each other). <Pretty normal. Goldfish breeding involves a lot of chasing, and it isn't always the boys chasing the girls. Rival males may chase one another, and females perhaps "test" potential mates by chasing them. There certainly is a certain amount of ritual goldfish go through before they actually spawn.> As its the large female bothering the male is it just bullying rather than sexual advances? or do you think I have sexed them wrongly? <The tubercles are usually a good clue to the male, but not all males show them...> the small male(?) in question seems very stressed by it all and in the last couple of days has been sitting on the bottom of the tank a lot, do you think it is ill? or tired? or, as I said, just very stressed? <Probably just stressed. How big is the tank? Four adult goldfish should be in something around the 55 gallon mark to be comfortable. Or else a pond.> It has no signs of illness other than being a bit sedate and the water quality is good. I would be grateful for any feedback. Thank you. <Hope this helps, Neale>

Comets and A red Cap, Mating or aggressive behaviour?  -- 04/16/07 I have a ten gallon with three comets, one calico and one red cap. <<That tank isn't large enough for one of these fish.  Please read: http://www.wetwebmedia.com/FWSubWebIndex/gldfshsystems.htm, http://www.wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm.>> All of them are roughly 3 inches and very happy.  When I came home today (lights were out) and they were thrashing through the tank after each other. Mostly after the red cap and then breaking into pairs chasing each other. Is it mating season? <<It's an over-stocked tank.>> My red cap seems exhausted, I caught it in my net and have it floating to give it a break, although the comets are still chasing each other, they keep coming up to the net and sniffing around her tail and mid section. Should I get a divider for the tank as I have no room for another tank (or for that matter more fish). The kids won the comets at a carnival 2 yrs ago. HELP! <<I'm sorry, but your tank is just too cramped.  Perhaps offer the fish to a friend with a pond, where your fish will grow to their normal 1-foot plus in length.  Lisa Brown.>>

Pregnant Goldfish??  4/14/07 Hi!  I am totally fish ignorant and happen to have three thanks to my little girl (two orange headed Orandas and a multi colored one that I don't know what he's called).  My one fantail (the smaller) started to looked bloated. <How large a system, fish?> I thought maybe I had overfed them or done something wrong and she was suffering for my stupidity, however, I woke up one morning and she looked like a deflated balloon and much more comfortable.  I assumed this meant she had laid eggs, but there were none to be found. (I assumed eaten) <Mmm, possibly> Now, two weeks later, she's blowing up again.  She doesn't swim upside down and is still active as usual, although when she is her biggest, she's a bit awkward.  What is happening and what do I do???  Could they have eaten all the eggs overnight or did she finally just un-constipate?  Thanks for any help.   Dara <Likely by far that this is a recurring food issue... and hopefully we can correct... Please read here: http://wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm and the linked files above. Bob Fenner>

Pregnant Fish - 02/09/2007 Hello there! <Mornin'!> Great web site by the way, your questions and answers are very entertaining. <Thank you... and a bit educational/instructive I trust> I have two little goldfish in a small aquarium on my desk. <Mmm, about how many gallons?> The fish are about an inch long not including fins etc.  One gold fan tail and one black moor.  The gold Fantail (Minnie) is suddenly much larger in the back side than Mickey. <Minnie got back> It's like she ate two balloons and shoved them behind her gills. Now I know fish don't get pregnant but I suspect she may be full of eggs <Mmm, no... not at this size> as she is otherwise happy and healthy and just as sprightly as ever despite her bulbous condition, always begging for food as soon as you look at her.  And Mickey is chasing her everywhere and has been for about a week. <Not atypical goldfish behavior... and not a worry unless "excessive"...>   He is also in perfect health.  I have bought some very leafy plants in the case that she needs somewhere to lay her eggs (forgive me I am a goldfish moron and am going purely on every fact (I use the term loosely) I have ever heard about goldfish). <No worries> If she is pregnant (so to speak) will I notice the eggs when she lays them, how long before that might happen, do I need to banish Mickey to avoid him snacking on his children? <Again... likely the development is simply "expression" of genetic potential... the fish doing what it's going to do... Do take a read on WWM re Goldfish Systems... and take care re maintenance of this small volume... too easy to get into trouble.> Thank you!!! Fish lover and fish idiot. Chanelle. <You're in good company here. Bob Fenner>

Goldfish repro., not   1/11/07 Yesterday we bough two goldfish our first ever, today we noticed tiny bubbles on the glass and on the plants could this be eggs help. <Mmm, likely just air... from dissolved gas in the new water... or air entrained through filtration, aeration... Goldfish are quite large when they reproduce... I have a concern that this system is not cycled... Please read here: http://wetwebmedia.com/FWSubWebIndex/fwestcycling.htm and the linked files above. Bob Fenner>

Will goldfish mating harm my female fish?    6/14/06 Hello, and thank you for such a wonderful website.  I Googled information about goldfish mating behavior and came across your site. <Thank you for this info.>   After reading many of the FAQs regarding mating/spawning behavior, I feel I still need to ask for more help and information. <Okay> Here's the situation:  I have a small (50 gallon) outdoor natural pond. It's very healthy, with lots of plants and snails.  A few years ago I bought 3 comets and 1 shubunkin (Manny, Moe, Jack, and Vinnie), who have grown and thrived.  They are now about 3 inches long.  Late last summer my dear mother passed away quite unexpectedly.  She had several pets, including an extremely large feeder goldfish named Bubbles whom she kept in a barrel pond outdoors.  We immediately brought Bubbles home and put "him" into the pond, where "he" was just as a happy as a clam.  Bubbles is about 6-7 inches long, and just huge.   Today I began to notice extreme spawning behavior amongst the fish, and now realize Bubbles is a "she."  The other 4 fish in the pond are relentlessly pursuing her, even though she's a whale compared to them.  (I don't know Bubbles' age, but she's at least 4 years old.) <Yes... seasonal... the "hots" for sure> I'm very concerned about Bubbles in that I'm afraid the other 4 fish will just wear her out. <You are right to be concerned here. In this too small volume there is too likely to be damage... Need separating, pronto>   I don't want to lose her. Not for a long time (in fish years) yet.  She's such a memory of my mom that it would just break my heart if something happened to her that I could've prevented.  The problem is, I don't know where to put Bubbles (if I remove her from the main pond, which is covered) to keep her safe (I'd have to devise a covered situation because we have raccoon attacks). <Good> I also don't know how long she'd have to be away from the main pond if I DID remove her.  How long does this mating behavior go on?   <During most all warm/er months... Spring... Summer into Fall...> If it's just a day or two, can the female deal with it? <Mmm, possibly... but I would not risk this in the size system you have, the number of fish...>   Another problem is that I'll be leaving on a two and a half week vacation starting in early July.  I have someone house-sitting, and so taking care of the pond, but.???   What would you do?!   <Mmm, keep the female separated... change out some water from the pond into the container where "Bubbles" resides, hide the food... more potential trouble from feeding during your holiday than it's worth feeding> Thanks VERY very much. Annette in Washington   <Bob Fenner in S. Cal.>

Re: Will goldfish mating harm my female fish?  06/14/2006 Hi Bob, and thanks for your speedy response! I just realized I erred in the size of my pond.  It's actually 100 gallons.  Do you think this makes a difference? <Some... but still too small for what all is going on here> If not, then Bubbles will have to live in a small barrel pond for the duration of the summer! <Mmm, do keep an eye on this container as well as situating it near the house to curtail large/r swings in temperature, water quality. You might want to add a air-driven sponge filter... Tetra's Luft pumps are great for this application, as well as their "Billi" filters or Jungle Products brand...> Again, thank you! Annette <Welcome. Bob Fenner>

Goldfish Breeding?   6/10/06 Hi there, I discovered your website, and I'm loving it! I'm honestly really sorry if you have answered a question similar to mine, or if the information I provide is inadequate. Oh, and I'm not really a goldfish expert, so sorry if the language I use isn't correct, hehe. Well, here goes. I have eight fish in my tank, all of which are just plain goldfish, but two, who are fantails. My mum told me that one of the fantails was a girl. One day, my dad came home from work and discovered one of the ordinary male goldfishes chasing the female fantail. <All goldfish are the same species (or di-hybrid cross), and can, will inter-breed> At first, he thought that he was somehow bullying her, but after a couple of minutes of research, I soon found out that it had something to do with breeding. Ever since I got my goldfish about a year and a half ago, I haven't ever considered my goldfish breeding. The female fantail that is still being chased by the male is a new fish. After a week or so, the male stopped chasing the female fantail. Just recently (about a week after the male stopped) the male has started chasing her again. <Tis the season... warmer weather, longer daylight...> I'm scared, I don't really know much about breeding fish, and hopefully my mum will be able to help too, as she and her family used to breed fish when they were younger. My question is this: Is this breeding, and is it normal for ordinary goldfish to breed with fantails? <Not atypical> Also, the female is constantly in the corners of my aquarium, and she doesn't swim around as much as she did before. <She or the male in pursuit should be placed elsewhere... Pronto> She is always on the bottom of the aquarium, but recently, she is coming up to the surface to eat. She used to eat from the bottom, waiting for the food to sink (I feed them flakes). Is this normal? Thanks for your help! Great website, by the way! Love from Krystal (12), New Zealand <I would move this female to another tank for its sake, safety. Mixing "rounder" type goldfish with "regular" comets can be problematical... in competing for food, space period... when reproductive behavior is added, trouble. Bob Fenner>

White sort of pointy spots (goldfish beh., repro)  04/17/2006 Hello! I searched the old FAQ's looking for a way to tell if the white spots on the cheeks of a goldfish are ich or breeding season indicators, <Hopefully the latter!> but wasn't able to find a descriptive comparison. <We/I do need/want "good pix" of most all commonly encountered such phenomena. Are you able to make some digital pix of these and send?> My goldfish who is about 3.5 inches long has little clear/white spots on his/her cheeks ( 3-4 on one, 7-8 on the other) that come to a kind of point. I read in one post that it is near impossible to tell the boys from the girls, but just in case, his/her front fins have a sort of "serrated" edge if that helps in figuring out if little fishy in a he or a she. <Do think this is a "he"... if the spots are as you describe, only on the cheeks> How can I tell if he/she is sick, or if in fact, my fish is a boy, and the other goldfish is a girl, and they are just about to do what fish do? They have been swimming around each other and rubbing each other, and chasing too. <Ahh! Even more evidence> If it is ich, is there a medicine that can be given with snails in the tank? <Mmm, not as far as I'm aware. All such treatments are deleterious to snails> Thanks so much for all of your help in advance. Sorry if these questions are redundant, I try my best in searching the old FAQs. The site is great, and I appreciate it very much. xxx kuniko <Doh tashi mashiite my friend. No worries. Bob Fenner>

Re: White sort of pointy spots (goldfish beh., repro)   4/21/06 The camera is in the shop, but I will send a picture as soon as it comes home. The spots are just on the cheeks though. Is there a time period in which the spots should go away if the are related to breeding and not ich? <Breeding... not ich> Will ick spots get worse (i.e. bigger)? <Only nominally... not much> The spots look pretty much the same as when I emailed last. Do the spots associated with fish love make a particular pattern? <Not really... in either case> The one's on my fish's cheeks look pretty random. If it is ick, I will have to set a hospital tank then because of the snails, right? <Yes, would> Should I treat both fish even if the other fish has no bumps or spots? xxx kuniko <... I would not move or treat these fish. I don't think this is a parasite. Bob Fenner>

Tank set up for newly hatched fry ... goldfish repro.   4/8/06 My goldfish laid eggs which I transferred to a breeding net  in the main tank to stop the parents eating them. The fry hatched overnight; <... usually involves a few days...> do I have to transfer them to a separate tank with its own filtration etc. and do partial water changes every few days, or will the conditions in the main tank within the breeding net be alright? <Mmm, well... better to move the parents, other fishes... But if you do move the fry, do so with a good volume of their existing water...> The tank is 130 liters and has three adult fish. I do a 1/4 water change every one to two weeks. Will this be enough to keep maintain the water quality for the fry? Thanks, Adele. <You should test various aspects daily, be ready to do change outs more frequently... Please read here for more general goldfish breeding/rearing info: http://wetwebmedia.com/PondSubWebIndex/pdfshbreeding.htm Oh, and congratulations! Bob Fenner>

Pregnant goldfish in winter? Not likely   - 03/26/2006 Stumbled across your site...very informative! Did a search but could not find an answer to my question... perhaps you can help? <Maybe> We have four goldfish in a 100 gallon horse trough, regularly cleaned and heated during the winter to the 40's degrees. These fish are about 4-5 years old, and one has developed bulging sides, and has stayed this way for three weeks. One of the other three seems more interested in the bulging one, at times. The bulging one appears healthy and eats well (not overeats.) Could this  be pregnancy? <Mmm... not likely> It is still winter weather with snow here, on and off...would the weather affect this? <Yes... but almost assuredly not w/o the temperature rising, staying in the 60's F. at least for days, weeks...> Thanks for any help you may offer. <What you're observing is far more likely some sort of tumorous growth anomaly... you could add Epsom and/or aquarium salt here... or just let time go by and see if this fish self-cures. I do hope/trust you are not actually feeding these fish at this temperature/season. Bob Fenner>

Sexing Goldfish    3/19/06 I just got a black moor today and I don't know what sex she is could you help me? It's got split tail fins and its pretty slender. <Not able to be sexed externally generally... See WWM re the prenuptial tubercles of males in season. Bob Fenner> Goldfish hybrids   2/23/06 Hello, <Hi there> I have a few questions for you regarding my beautiful breeding goldfish. I have a large orange Ryukin and a medium black/brown Oranda that have spawned. The eggs are developing nicely ( I can barely see the cell divisions with the naked eyes, but alas am doing my best). My questions are as follows ( after countless hours of attempting to research these questions on my own): 1: Do you have any links that show pictures of this hybrid? <Mmm, I don't think so... will be a mix of both varieties and some "blends" as you state> 2: the eggs are incubating at 80 degrees, will the fry be deformed and will the incubation time be less than 4 days? <I'd keep these a bit cooler (the low seventies F.)> 3: When the fish spawn, why was I unable to see milt from the male, even with a light cast on the experience? <Isn't all that apparent... and all that much... professional breeders use 2,3 or more males per spawning female to insure fertilization> 4: How soon can my female replenish her eggs and ultimately breed again? <A few weeks under propitious circumstances> 5: I would like to see documented embryogenesis stages of goldfish eggs, what link, if any, can you recommend? <I thinks someone has sent this very info. today. Please check the dailies re... Perhaps it was you in a later e-mail> Your website is the best I have seen in regards to information, thanks a million and I am anxiously looking forward to your response. Michael- <There are some fine "goldfish books" in print. Do you have a collection? Bob Fenner>

 Goldfish Embryology and fry development with figures!   2/23/06 Hello again, <Ah, yes... it was you Michael>        Michael here again. While waiting for a response to the questions I had asked I came across one of the answers. The following is an absolutely fantastic, extremely detailed article on goldfish embryology, the stages of development of the fish inside the egg, and the stages of fry development of the fry....ITS FULL OF FIGURES.  It is very scientific however, but I do enjoy reading a detailed and quantitative paper, especially on something so precise. THE EMBRYOLOGY AND LARVAL DEVELOPMENT. OF THE GOLDFISH (CARASSIUS AURATUS L.) FROM LAKE ERIE. HELEN I. BATTLE. Department of Zoology, University of Western https://kb.osu.edu/dspace/bitstream/1811/3077/1/V40N02_082.pdf Thanks again and I hope to hear from you soon. These figures of development are going above my hatching tank, something interesting to compare with since watching the eggs develop is about as exciting as watching grass grow. Take care, Michael <Thank you for this. Bob Fenner>

Gold Fish Breeding   2/22/06 Hi my name is Dan I have a pond that is about 10' wide and 3' deep. I have around 20 goldfish in it not sure about the type. I know that I have at least 6 female's and two of them are showing signs of breeding. I was looking at the pond the other day and noticed that I <I> had some baby fry. I would say 1/4 '' to 1'' in length and all my other goldfish are 3'' to 8'' . I had put them  in last year around September 05 hoping to breed them this year. Could these fry be from last year or could they have gotten this big from this year. <Likely from last year...> We have had some warm weather this year it has gotten around 50 to 60 degrees for a few day's and dropped to the low teen's would that have had an effect on their spawning ? <Yes> Also could these couple of warm day's have caused them to spawn early? <Possibly, but doubtful... takes some time for the fish to "come into breeding condition"... weeks of warm/er weather> If so will I still be able to hand breed them in a separate 80 gal. tank? <Mmm, not yet> Also if I can still breed them in a different tank how may time's will or can they spawn. I have been looking this up for a while hoping to do some breeding so any info on this matter will help a lot                                           sincerely Dan <See here: http://wetwebmedia.com/PondSubWebIndex/pdfshbreeding.htm and the Related FAQs linked above. Bob Fenner>

Lionhead Goldfish  - 02/20/06 I have a female Lionhead that looks like she is very pregnant.  She is in my Koi Pond with several other types of fish, but no other Lionheads.  I was told by a neighbor that I need to find a male Lionhead so that she would lay the eggs, otherwise, it would kill her.   <Mmm, no> I checked with a pet store and they have 5 Lionheads, but said that they can't tell whether they are female or male.  Is my neighbor right in that I need to find a male? <All goldfishes will interbreed (like domestic dogs they're all the same species, actually di-hybrid cross), otherwise will re-sorb the egg material...> If so, how do I insure that I am purchasing a male? <Can be sexed at times... Spring mostly... though not easily done by the uninitiated. I would not worry or seek out a male or other Lionhead though...> Thanks for your help, Ric Maxfield Kapolei, HI <A hu'i ho! Bob Fenner>
Re: Lionhead Goldfish  - 02/20/06
I don't know if it makes much difference, but I'm pretty sure now that she is a red cap Oranda rather than a lionhead. <Mmm, nope... unless you do intend to breed this fish, want a greater percentage of young that look like this> I found a picture on another site of a red cap and it matches her perfectly. Thanks again, <Aloha, Bob Fenner>

2 Goldfish spawning & Fry Questions.....  - 2/15/2006 HI!    After much searching on the web, I haven't found much out, so I thought maybe you could help!   My first question is this:  Is there a way to Stop my fantail calico goldfish from spawning sooo much??? <?> For 8 weeks now she has spawned 1-2 times a week every week.  That just seems like a ton,  and we feel bad for her since the males chase her vigorously for hours on end.    <Separate from the males...>   My second question is about fry.  We kept some of the fry and are raising them. We have 8 that are in a 5g tank, but they still seem VERY small for being 6weeks old. They are maybe 1/2"to 3/4" big is all, still pretty translucent.  Should they be bigger than this at 6weeks???    <No... this is about it>   Any help would be GREAT! Thanks so much :) <Congratulations on your spawning, rearing experience. Bob Fenner>

Goldfish Is Not Pregnant   1/7/06 Hi my name is Daleigh I have a 10 gallon fish tank with about 4 small goldfish in there but I bought a fish yesterday and I thought it was just deformed or something but to find out I believe it is pregnant!!..And it is laying in the grass in my tank, its been there for a while. I bought and net box so when she does have them , I can put the babies in there so the adults wont eat them. But my question is when will they hatch if she is laying them now? Please help never had a pregnant fish before! Thank you < Your goldfish is probably sick with an internal bacterial infection and not pregnant. Do a 50% water change, vacuum the gravel and clean the filter. Treat with Metronidazole as per the directions on the package.-Chuck>

Goldfish Fry - 10/21/2005 Hi, I've read through the questions on your site that have been sent in regarding the reproduction of goldfish, but I have some questions that aren't answered, and I'm not having any luck through Google.  <Well, let's see what we can do.> We have two black moors in an 18 gallon tank.  <Err.... too small.> Not long ago we noticed that one of them had some white spots on the leading ray of it's pectoral fins; initially we thought it might be a fungus, but this was followed by what we mistook for aggression toward our other black moor, and now know to have been spawning. A day after we did our routine water change we spotted some fry in the tank; we were completely surprised since we didn't even know that our fish are of opposite sex or that the "fighting" we were seeing was spawning. Sadly, it would seem that we "vacuumed" up many of the fry knowingly when we did our water change, <Yikes!> and we were only able to gather up 3 of them before their parents devoured the remaining 4 or 5 that we spotted.  <Mmmm, tasty.> Now we have these 3 itty bitty fry (only about 5mm) in a very small tank (only about 5 gallons) along with a sponge filter, and have been feeding them a couple of drops of Liquifry each day for the last two days. If they survive, we intend to purchase a much larger tank for their parents, <Ah, good. Should do this regardless, if possible.> and when the little guys are large enough, move them into the 18 gallon tank that we have. My questions are: Is the 5 gallon tank we have the fry in large enough for now?  <For now, sure.> What are the chances that all or any of the fry will survive (we are doing 25% water changes with good quality, well balanced water every 2 days)?  <Chances are pretty good for 'em.> How quickly will they mature into something that resembles a goldfish, <Probably a few to several weeks.> and is there a way to speed this process up?  <Very high quality foods. Newly hatched baby brine shrimp, for one.> What temperature should we be keeping the fry at? <Probably somewhere between 65*F and 75*F.> Thank you much, -Lela <Sounds like you're doing great so far! Wishing you well, -Sabrina>
Goldfish Fry - II - 10/22/2005
Dear Sabrina and WWM, <Hello, Lela!> Thank you for your reply. We are definitely planning to buy a much larger tank for our two original black moors, but were trying to hold off until December because we have purchased a house that won't be ready to move into until that time. Our little apartment won't accommodate the type of set up that we want to get, but now you have me worried. We have had the two original black moors in their 18 gallon tall tank for over a year, and they do seem to be outgrowing  it, but seem healthy and happy. Will they be ok for another two months in there?  <Oh, sure. A couple of months is okay. I would aim, if possible, for a 40 gallon tank.... A 30 at the least. Might actually be most cost-effective to go with a more standardly available 55 - some places, a "kit" including very basic components is cheaper than a bare 40 gallon tank.> Also, you mentioned that the fry should be kept at between 65º and 75ºF; we live in Texas, and though we keep the air conditioning on very low all day, room temperature hovers around 76º or 78º. Is there another way to keep our fish cool? <76 o5 78 is probably okay.... though cooler would be better. If you wish to decrease the temp some, you can aim a fan across the surface of the water. This will probably drop the temp a few degrees.> Thank you again, -Lela <All the best, -Sabrina>
Goldfish Fry - III - 10/22/2005
I just re-read my original message to you, and we *unknowingly* vacuumed up some of the fry from the original tank, not knowingly. Goodness, we sound like monsters knowingly vacuuming up those cute babies! Definitely not the case. <Heh! No worries, hon; I know/knew what you meant.... in fact, I fear it may have been a poor editing/formatting job on my part. I seem to remember that word having been misspelled.... or perhaps messed up from our webmail system, or something.... and so I quickly changed it before sending, as we post all these on our site; must repair grammatical and spelling errors when possible. My apologies, and no, you're not a monster! Take care of those young'uns! - Sabrina>

Goldfish May Be Breeding  9/29/05 Hello Robert < Chuck here this time.> I am sending you this email hoping you can answer my question about my goldfish, as I would like some advise on how to treat the illness. We have got 2 goldfish in a pond feature in our front garden over here in Perth WA. We have noticed that 1 of our goldfish has got many white lumps of some sort over its body and near its eyes. The fish itself has not changed in anyway it still eats well but I am concerned that the lumps are appearing more over its body and might result in my goldfish becoming ill. Could you please help me and advise on what the lumps could be and also what we need to do to get rid of them. Thank you for your time in this matter. Kathryn Lawton. < Males develop little bumps over their gill plates and pectoral fins when they are getting ready to spawn. Look at your goldfish closely and then try to find some photos on the net to compare to your fish.-Chuck>

Small goldfish spawning?  8/31/05 I have 6 small comet goldfish in a 25 gallon tank, I have had them for about 3 months from a pet shop. Each fish is about 4-6 cm long. <Too small to reproduce> A few days ago I noticed some small white/grey spots on the bodies of some of the goldfish, I did some research and thought that this might mean that they are males (I cannot tell if there are spots on the gills as well). <The so-called pre-nuptial tubercles are located only on the head region> Today one of the goldfish (one without the spots), started shaking a bit and looked like she might be laying eggs, but is smaller than most people say the breeding size is. I could not see any eggs, but one of the other fish was pecking at the gravel underneath her. Was this her spawning? Is she or the others diseased? What should I do? Thanks Kathryn <Unfortunately, it reads that your Comets are infested with a parasite, likely "ich"... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm and on to the linked files above... If so, you will want to carefully use a commercial anti-ich medicine. Bob Fenner>

Mystery Fish, Reproduction, Rearing - 08/19/2005 Hello, I have read through your site many times, it is great. <The whole site?  Many times?  Wow!  I've been answering questions for a few years, now, and still haven't scratched the surface....  'Tis a big site!> But I did not find a few things I was looking for.  I have 8 fish, all less than 5" in a 33 gallon tank with filter, live plants and other decorations.   <What kind of fish?> My two biggest fish, one 5" and one 4" have been chasing each other.  Today the smaller one started letting go of her eggs.  What I am wondering about is, the larger fish seems to be acting as the male but with goldfish shouldn't it be the smaller one? <Ahh, so at least this pair are goldfish?  You might be a mite overstocked....  just something to consider.  In any case, just like with people, there are exceptions to any rule.  I recall in high school, I dated a fellah three years older than me whose head didn't quite reach my shoulder.  Uncommon, but possible.  Same with fish.> Also, is there any way to get the male to fertilize the eggs in the tank? <If they are spawning, the male will fertilize them as the female lays them.> I will have to move the eggs as I have too many fish to move them out of the tank.   <Be quick, or they'll be eaten!> I also have a large filter that does 100 gallons an hour, with this kind of turnover if the male does fertilize won't it get filtered out too quickly to fertilize?   <Not an issue....  Goldfish have spawned in streams with no intervention/help from man for many, many years.  If the eggs are laid, and the spawning pair included a healthy, fertile male and female, the eggs are fertilized.> This has caught me totally off guard, I never expected them to start this.  Thank you very much, sorry if I asked questions you have already answered.  Sincerely,  Alden Knight <No worries!  Wishing you and your possible new goldfish spawn well,  -Sabrina>

Goldfish crosses 8/19/05 Hope you have a second to help me out, I'm very confused all of a sudden. <Mmm, am pretty much that way all the time...> My fish have been spawning almost daily since April 22nd and still continue to do so, so I definitely know how that works and who are the males and who are the females. Here's part question/part confusion.  I wrangled 13 fry on July 19th.  Some for my brother, some for a neighbor.  They are in a 10 gal tank on my back porch.  I noticed 2 days ago doing a water change that one, and only one fry is a fantail. <Happens> Here's were I'm so confused.  I have one male fantail Shubunkin and one female Ryukin. Now, unless this fantail fry quits growing longer and starts growing in height, it's a Ryukin.  But, it looks like my male Shubunkin. What female had this baby fry if not the Ryukin??? My females are Sarasas, Shubunkins and common goldfish none are fantails. <Could be any... but likely the Comets... they just are more active spawners...> I hope you can and don't mind solving this mystery for me.  I've tried to Google for my answer but I guess I just don't know how to phrase it. Thanks for reading and if you don't respond, that is perfectly ok with me.   Edie <Goldfish that have been crossed a good deal (most domestically have) do not "spawn true"... and they are all the same species (actually cross)... somewhat like domestic dogs... Bob Fenner>
Re: Goldfish crossbreeding... results 8/20/05
Thanks so much for your time.  I was thinking it had something to do with lineage. Edie <In a manner of speaking, it is... just a far "looser", dynamic lineage than many folks are aware of. Bob Fenner>

Goldfish & having babies 7/19/05 My wife wanted to know if Gold Fish die after they have babies? The mother seems to have disappeared after birth. Thanks, Bill Warren <Mmm, no... don't perish after breeding... Might have jumped out... or if outdoors, been predated... Bob Fenner>

Spawning goldfish? 7/15/05 I have an Oranda and a  Pearlscale goldfish living together. I'm pretty sure the Pearlscale is a female  and the Oranda a male as they have been showing signs of courtship (every  morning the Oranda follows the Pearlscale quickly around the tank with his face in her back end). <Mmm, not necessarily indicative> This behavior lasted about two weeks and nothing ever came of  it. The last few days I haven't noticed any of this. The Oranda never got the  white spots I've read so much about, the Pearlscale is very round but no more then normal (I've had her for a year), and no eggs were ever laid. Was I wrong  to believe this was mating behavior? <Likely so> Was she unreceptive and he just gave up? Is  that possible? Just wondering. Thanks, Christine <Perhaps your fish are too young... maybe not properly conditioned (through feeding, water changes...). They might have spawned and eaten the eggs... Bob Fenner>

Poor English, Goldfish Hi there I have two questions 1 I have 9 goldfish some fantails, common and moor and also have two paradise fish and some minnows they all get on (minnows are being eaten) but we know we have at least two males and there have been signs of mating but they are not I check everyday for eggs will they and when do they and 2 I have another one that I'm sure is egg bound and has been for a while she has just started floating upside down as no balance what else can we do to relieve her    thank you <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/gldfshdisease.htm and the linked files above. Bob Fenner>

Flaming Goldfish? I recently had a goldfish that just combusted can you tell me why this is so. <?!> Every now and then it would swim on its side.  I thought that maybe it was getting ready to lay eggs so I moved it to another tank by itself.  I kept close watch and then it got really depressed and thin.  I was afraid it would die so I put it back with the others.  It's symptoms returned and the other night it just combusted.  I don't want this to happen to the others so can you give me any idea as to why this happened.  Thanks Elizabeth <... perhaps nutritional... environmental... Maybe your fish is becoming egg-bound? Please read on WWM re Goldfish foods/feeding, systems, disease... Bob Fenner>

Pregnant goldfish My white goldfish is pregnant, going on two weeks, and she looks like she¹s going to explode (about 5² long).  Today, I noticed that there are now large red areas on both sides, kind of like blood inside.  She has continued to get bigger and bigger.  Is something wrong? <Sounds/reads like it> Prior to becoming pregnant, the male was riding her side.  I have 4 gold fish in a 100 gallon outdoor pond, plenty of foliage, water well kept/clear, oxygenating plants, etc. Reesa Doebbler <This fish could be egg-bound... might be diseased otherwise... I would treat it, and probably the other fish in this size system, with Epsom Salt... as gone over and over on our Freshwater and Pond Subweb sites. Bob Fenner>

Pregnant goldfish full of roe We have one goldfish in our Koi/goldfish mix that appears to be full of roe.  She is quite swollen in the abdomen and has been so for a couple of months now. <Mmm, if it's been months the fish may be "egg-bound"... or perhaps just fat!> Because we weren't sure that she wasn't carrying a parasite or disease, we moved her  to our smaller (600-700 gal) outside pond where she now resides by herself. I checked your FAQs and understand that Epsom salts, added to the water, may make her discharge the roe.  Is this correct? <Yes... a safe and often effective cathartic for such blockages>   But is she retaining the roe in the first place because she isn't with a male who is available to fertilize the eggs? <Doubtful> Should we put her back into the pond with the other fish instead?   <I would try the Epsom Salt in a small/er container first... for a week or two...> Then, if she discharges the roe and a male fertilizes it, probably all the little ones will get eaten by the Koi and other goldfish. <Not all... there are many and these are not as palatable as many folks think> If we elect to add Epsom salts to the water, how much should we add to a 21 gal holding tub and how long should we keep her in that? Thanks, Sue Sweeney <Ahh! A good two teaspoons... for a week or two should do it. Do monitor ammonia... be ready to switch out polluted water. Bob Fenner>
Re: Pregnant goldfish full of roe
You guys are the greatest and I thank you for your time! BTW, don't overlook the entertainment value of your FAQs. Andre and I laughed ourselves silly over some of the entries last night as we looked for answers about our pregnant goldfish. Sue Sweeney <Tis fun! BobF> 

Reproducing goldfish Ermm - there's eggs everywhere, so looks like it was a mating ritual'¦the 3 other goldfish are still chasing her and more eggs coming out'¦do I just let them be until they are done, then collect the eggs or do I remove both her and the eggs now? <Best to remove all adults, leave eggs in place> I am sure this is on the site somewhere, but I have searched and been unable to find. Weird note, these goldfish were supposedly babies when purchased, only 2 months ago- I read that a healthy breeding age was 1-3yrs old'¦they did go through a growth spurt tripling in size, could the bloodworms and brine shrimp be responsible and should I stop feeding them these? <Mmm, perhaps these fish were older than you thought. Not the food> Again thanks for your help and sorry for the horrendous grammar and spelling. Brittany <Luckily your email addy was on this copy... the "tray", means to respond to your mail did not come through... This is happening more and more. Bob Fenner>  
Re: Reproducing goldfish
Thanks again for your help!!! Goldfish have all settled down now and apparent aggression (lol breeding) gone. <Ahh, good> Hrmm, wonder why the mail to: isn't populating... weird since very simple call. Not sure which box I originally sent from, but I run a freePOPs Linux app to avoid logging into hotmail accounts, that maybe causing some issues- so more than likely it's a my side issue. Thanks for the heads-up. Hehe, I'll just start tagging email in the future, still much simpler than logging into 50k different email addy's :-) <Wish I knew a simple fix... we get a couple, three such "unanswerable" queries per day... Am fearful folks are wondering where their responses are, are hopefully seeking alternative input. Bob Fenner>  

Goldfish, WWM Hey... My name is Emily! I just bought a gold fish the other day to put in the tank with the one I have had for like the past 3 months! Ok...That isn't my problem! My problem I ...I think the new goldfish is pregnant! Well carrying eggs! What do I do? How can I tell if she is going to let her eggs out? Do I need to move her some where else? Can the filter suck up the eggs when she releases them if she is really pregnant? HELP! Emily <Emily, please go to our site (URL above) and read re Goldfish reproduction, feeding... Bob Fenner>

Goldfish breeding Dear WWM crew, I know you all get tired of people's questions so I'll make it short. I have a female calico Shubunkin that spawned in one of my aquariums with a red and calico fantail male. I was wondering what the fry will be as they grow up? Will they be deformed? What should I expect? Thanks, Jarrett <The young will look like non-descript fusiform shapes as young, develop into a mix of traits of the parents, including color with age/growth. All goldfish are the same species... sort of like domestic dogs... can and do interbreed. Bob Fenner>

Death of Goldfish Through Aggression (Goldfish Love, According to Don) Hi all, I've been going through all your FAQs and have seen lots of questions about goldfish aggression. However, this is a slightly different case, and I wonder if you could help. We (had) 3 goldfish, Nemo, Sparkle and Tiger. Tiger is very much the rampant male, particularly this time of year towards Nemo, and Sparkle has often tried to get in the way between them when Tiger chases Nemo. It always seemed to be lust, to be honest! However, this morning we found Nemo lying dead at the bottom of the tank. She was terribly bruised and had some of her back fin missing. She has been in excellent health her entire life (around eighteen months) so we're sure it wasn't due to ill health. In addition, Sparkle appears to have bruising around the one side of her head - is it possible that Tiger attacked Nemo, and Sparkle got in the way? Sparkle is now fine in herself, swimming around like usual, but I'm concerned Tiger could turn on him too - although I haven't seen him behave like this towards Sparkle before. Should I be concerned? Thanks, Kate <Goldfish love can be aggressive. If Nemo was the lone female then things should calm down. But should you be concerned? Of course. Keep an eye out for more aggression and be prepared to separate them. Don>

Pregnant goldfish Sun, 27 Mar 2005 I know you must get thousands of e-mails. I am sorry to add to your load. Just a quick questions, I long will my goldfish be bloated with eggs? <Should be no more than a week or so...> I am pretty sure she has eggs in her tummy but she has had them for a week and I wondered how long she will continue in this state. She is really fat now and I wonder if she will explode!! Thanks for all you do. Dana <Your fish may well not be full of eggs, but perhaps suffering from a "dropsical condition"... Please read here: http://wetwebmedia.com/FWSubWebIndex/gldfshdisease.htm and on to the Related FAQs linked above... Likely addition of Epsom Salt will help here. Bob Fenner>

A Good Question - Culling fry humanely When breeding goldfish and getting your spawn, what is the most humane way to cull the deformed or inadequate goldfish fry? Regards, M <To place them in a bag with little water, freeze them. Bob Fenner>

UNWANTED REPRODUCTION Dear crew: A few weeks ago I got some goldfish. We have about 8 in a 10 gallon tank. <Yikes... this is way too much life in this volume> Recently 2 of the comets have started, I think, to spawn. I am totally new at this. The male has white bumps on him. Do we need to move them into a new tank alone? <Mmm, if you don't want them to spawn I would not... if you do, you'll want a much larger tank... at least forty gallons... to raise (some of the) young in> We are thinking about getting a 10 gallon tank to put them in. That is all I have the money for. I don't know what to put in the new tank or what to do at all. I want the eggs to live if the female has any. please hurry. I don't think I've got much time at all. I just want to buy the necessities before the eggs come. Has been going on for 1 and a half days. Thanks loads! <I would actually give away all but two of the fish you'd like to keep... for a short while depending on how big they are now... Goldfish need more room... ultimately a good 15-20 gallons per individual... Please read here re their systems: http://www.wetwebmedia.com/FWSubWebIndex/gldfshsystems.htm and the linked files above... Bob Fenner> 

Goldfish repro. questions How long are goldfish pregnant? How can you tell?  How can you tell male from female? What do I do before during and after laying  of eggs? Will the other fish eat the eggs? Tammy A.  Romo <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/gldfshreprofaqs.htm Bob Fenner>

Goldfish: problems with breeding Dear wetwebmedia.com, I have a common goldfish in my tank, I thought he/she was lonely so I bought 2 Shubunkin Veiltails and 1 redcap veiltail. I also did this because I wanted to breed them together to start a hobby. I am unsure of their gender as they do not show any kind of tubercles but the 3 Veiltails are quite wide bodied but I guess that is how they are bred. <Yes... and the tubercles will only show in mature males in breeding condition> I have raised the temperature of the tank so that it is a steady 25 degrees Celsius, <77 F> have planted some long leafed aquarium plants and do a 30% water change per week. I am writing to you to see if I am doing anything wrong. All the fish are happy but no signs of mating have occurred (i.e. chasing) so I was wondering if I have to stimulate them as I keep the tank temperature the same all year round because it is in my room.  Please help!!!  Best of luck M <Sounds like a very nice set-up... and you're doing all right as far as I can tell... Likely your fish are just too young to spawn at this time... give them some time (six months or so) and try periodically raising temperature (a couple of degrees C.) along with your water changes... this and good feeding, maintenance in general ought to reward you with breeding behavior... Now, do you have enough room, capacity for raising young? Bob Fenner> 
Re: Goldfish: problems with breeding <
Now, do you have enough room, capacity for raising young? Bob Fenner> I have a hexagonal tank which is about 32 centimetres long along the longest bit and is about 28 centimetres high, so I will be getting a bigger tank soon so that my fish will have space to grow. Also I would like to know: will all these fish happily breed with each other? <They may... all goldfish are interbreedable> How long would you say in inches a goldfish is when it becomes of breeding age? <Overall... some at 2 1/2-3"... as young as six months...> Should I have a separate tank for breeding set at a higher temperature to stimulate breeding when the goldfish mature? <Yes... this is what is done in commercial operations. Bob Fenner> 
Re: Breeding Goldfish
<<Will tubercles show on the males and the females fill with eggs as soon as these fish hit their breeding age?  Do you think that any fish store will take my 'good quality' goldfish to sell (how much per fish do you think?)?  You have been most helpful with my problems>> <Please read here: Breeding Goldfishes  Bob Fenner>

Goldfish, plants and breeding Dear crew, Just wanted to know but how do I 'inspire' my goldfish to breed?  Can adding a live aquarium plant help?  Martin Slough <Mmm, this can definitely help... trigger reproduction... along with conditioning (feeding), keeping males and females separated... and particularly by raising temperature of their water... there is MUCH written re: this, the most, longest cultured of aquatic ornamentals. Bob Fenner> 

Goldfish breeding, clarity, lack of follow-through a few years ago I bought a goldfish. recently I bought another Goldfish that has white spots all over it's body, could this be a male? <Mmm, not all over... this is a disease> <<I must have exaggerated, it's just on the pectoral fins>> the first goldfish is generally big. how can I get them to mate, they don't really seem to notice each other. the male is smaller than the female. Do I need to raise the temperature in the tank or give them a different diet or what? regards Martin <White "prenuptial tubercles" can occur on males... in breeding season/condition... not on pectoral fins... see where you were sent re Goldfish Disease: http://www.wetwebmedia.com/FWSubWebIndex/gldfshdisease.htm and the blue links above. Bob Fenner> Breeding... what? Dear team, how do I get my 2 fish (male + female) to breed together. do I separate them temporarily, raise the temperature of their tank or do something to their diet? I'm clueless of what to do!!! please help me <Heeeee! What, which species? Bob Fenner> <<they are just plain ordinary goldfish, I think they are feeders because they are orange and don't have long tails>> <Ahh... my friend... learn to help yourself... see this index: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm Go there, scan down to the area about goldfish, READ the section on reproduction. Thank you, Bob Fenner>

Pregnant bubble eye goldfish? I recently purchased a bubble eye gold fish, and it looks like it might be pregnant.  It has a unusually big stomach and looks very uncomfortable.  I was wondering if there's a way to tell for sure, I have already separated it from the other fishes.  What can I do to help it? Thanks <Mmm, not likely pregnant... the species are egg-layers... or egg-bound... but perhaps overweight even for an egg-shaped breed. What do you feed this fish? Please read over our coverage of goldfish... You can find all here: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm Bob Fenner>

Have lot's of egg's Hello my name is Faye and I have a question for you - please help. <Hi...this is Jorie...I'll try to help you!> I separated my gold fish and put male and female together about a week later I went to work still no babies...went to work the next day nothing; I came home and found lots of eggs - took both mom and dad out now I need to know how long before they hatch (if I'm lucky), or should I have left them in their with the eggs?> <You absolutely did the right thing by separating the fish and their eggs, as the parents would gladly have munched them all up!  Incubation depends on the temperature of the tank...somewhere around 5 days if the water's at 70 degrees F, and somewhere around a week if the water's a cooler 65 degrees.  What type of setup do you have the eggs in? Be sure there isn't too strong of a filtration, as that will suck up the eggs and fry (once they hatch).  Also, you'll need to either grind up some flake food for the new fish, or you can purchase something like Hikari's First Bites (essentially the same thing...very fine powder with lots of nutrition packed in there). Hope you are able to raise your babies through to adulthood! Good job on providing a healthy environment that your mom and dad fish wanted to breed in!>> Thanks, Faye Sutton <You're welcome, Faye.  Good luck! Jorie>

Goldfish Sex I have a lone goldfish and was thinking about how I truly had no idea as to its gender. That go tm e wondering if it should show some mating sign. I read that the females produce pheromones to stimulate the males, but do the females lay eggs regardless of their environmental conditions? Since I have seen nothing unusual should I assume that my goldfish is a male? <<How big is the fish? Female goldfish will not, on average, lay eggs unless she is properly inspired. Normally, to induce spawning in goldfish they must go through a "cold" phase, like hibernation, then be properly fed with some good quality foods, including live, and it would help to have a male present. I am not sure, but there are probably websites you can do searches on for this information. I wouldn't worry about it, chances of them spawning in your tank are slim. It happens, but it's not something that happens very often by accident. Do not assume it is male, since goldfish are impossible to sex, except by folks who have already bred them and know just what to look for. -Gwen>>

Goldfish sexing Hey!    Thank you for the information! I have had my goldfish for about a month and a half.  He or She is very small. It is 2in. long.  I would like to know what gender it is.  Is there any possible way I can tell, or would I need to take it to a pet store? And again thank you for e-mailing me back! < Typically the males are slimmer than the females and when they get larger and ready to breed the male will develop nuptial tubercles or little bumps on the forehead.-Chuck>

Goldfish Population Dear Fenner, I have a small garden pond which has recently become overstocked with goldfish which are growing larger by the day could you suggest my kindest option to remove some of them 1. Put down by a vet 2. Put in local wild lake, would they be invasive of local environment 3. Other? <My "other" options include contacting, selling your excess stock to a local fish store or garden center, and giving them away to other folks with ponds, aquariums through an ad, contacts with a local fish club. Bob Fenner> Please help Best Wishes Nick.

Goldfish Babies! Please help me! My daughter won a feeder goldfish at a fair. I thought that it would not live to long because of where we got it. But 3 days later I can home from work to find 30-40 little babies in a single goldfish round bowl(2gallon). I did get a larger tank.  What do I do?? Take mom out?? It looks like she may be eating them because there are not as many in the bowl. I have never had a golf fish before. Please help me. Thanks, D <<Dear D; She is most likely eating them. You can remove them with a siphon, just suck them up into a bucket, keep them in a separate container, and be sure to feed them three times a day, but do not overfeed each time...do daily 50% water changes to keep the waste levels down. Have fun! -Gwen>>

Fantail Fun Hi. I am new  at this and I have a question for you  and I hope that you can help me. I have a fantail fish his name is Mix. I looked for those white pimples on Mix but I did not see any on Mix. But he is big I am just wondering if I got a boy instead of a girl. And I looked at the other two also. Can you help me this is my first time having fish. Thank-you. Jessie. <<Dear Jessie, congratulations on your first fish! I hope you enjoy keeping him and his friends. I cannot tell you if he is a boy or a girl, because they look alike. When they breed you can tell the boys because they have the white pimples, but only while breeding! Usually in the springtime, after a very cold period of hibernation. I guess you can just assume he is a boy if you like :) -Gwen>>

Goldfish... breeding behavior Dear WWM, I have 4 goldfish. 3 comets and one fantail. I have had them since last   February. For the past month, the 3 comets (which are males) have been ramming   the fantail (which is female) into the tank walls or gravel or into each other.   I began to look for solutions because I thought that they were just being   violent. Soon, I came to realize that they were nearing the breeding period of   the year so I checked the males for those pimply things on their gill plates.   Tada! There they were. Is it bad to have 3 males and 1 female in the same tank.  If so, should I get 2 more females? < Either get more females or remove some males. In the meantime you could add more cover to the tank to give her a place to rest and recover.-Chuck> Eugene

Goldfish laying eggs Greetings. Have spent hours trying to learn about goldfish laying eggs...couldn't find what I wanted...so am writing. Thank you in advance. We have 4 goldfish in a 25 gallon tank. Water is great, they are healthy. The bubble-cheeked fish has been hanging upside down in a plastic plant for days. I do not believe she has eaten...barely moves at all. Is she laying eggs? What the heck should we do? Will the bigger, more aggressive Molly bother her/them? Please respond if you can...I'll try the library in the meantime. Thanks again! < Unfortunately I don't think your goldfish is laying eggs. When fish are stressed from things like poor water quality, old food or too high a temp, then their resistance to disease starts to break down. Some of these break downs occur externally, but many of the break downs occur internally. I am afraid your goldfish has a case of bloat/dropsy. It has an internal pocket of gas that won't let it swim normally and so you find it swimming oddly and caught in the floating plants. I would recommend treating the fish with Metronidazole with a 30% water change every other day until the fish begins to eat again. If you medicate the main tank then you will need to watch for ammonia spikes because the good bacteria that break down the fish waste may be affected.-Chuck> Cindy

Pregnant Goldfish? Goldfish are new to us. We're thinking one may be expecting. < If your goldfish is getting very fat then it could be caused by a couple of reasons. It could indeed be pregnant and get ready to lay eggs. It could be an internal disease in which bacteria are expanding in the gut causing gas. This is also called dropsy. The poor fish could also just be fat from overfeeding too. > If she is and gives birth will the other fish eat the babies? < If eggs are laid then the other fish including the parents will eat them.> Do We need to put it in a separate bowl with the babies or away from the babies. < It takes two to tango. The eggs are fertilized by the male when they are laid. No male means no fertilization and no babies.> If so, how long before the babies can reunite with the other fish. < When they are big enough not to be eaten.. What do we feed the babies? <Baby brine or finely crushed flake food. How long before the babies are born? < No way of telling.-Chuck> Thank you Becca 

Goldfish and their Lack of Breeding I have installed an outdoor pond, it holds about a 1000 litres of water. I have 23 various Goldfish ranging in size from 2.5 - 7 inches in length. I built the pond in March 2004 (Autumn). <Very nice! I find having a large outdoor pond is very relaxing.> It has Water Lilies and other Oxygenating plants in pots as well as a Fountain. The fish all seem extremely happy in their environment, and from time to time seem go through the process of chasing one or the other, which I am told is part of their breeding ritual. <That is a good sign to show that the goldfish are getting in the mood, though it doesn't mean that they always go threw with it.> However, it is now February 2004 and we have seen no sign of young fish. <Perhaps the fish don't have a proper place to lay the eggs.  But most likely the fish are simply eating the eggs/young before they have a chance to grow.  Unless you have a breeding area, or separate tank to move the goldfish that are attempting to breed then it's hard to have them successfully breed in a pond.  I suggest you look at links such as www.goldfishinfo.com, or check out the WetWebMedia pondfish section.  Those should offer some great info for you.> This is my first pond and I am really puzzled, can you please help. Thank you.         <Breeding goldfish is not necessarily hard to do, but needs certain set-up to ensure the eggs and young survive. check the links out, and good luck.-Magnus>

Goldfish Fry help I had 2 red and white Orandas in a 2 gallon tank for over 6 months after which one of them died. <That is to small of a tank for a single goldfish let alone 2.  It is hard to keep water parameters correct in such a small volume of water.> so we moved the one remaining into a 10 gallon tank for about a month and then added 3 more Orandas (would be upgrading soon to a bigger tank as I feel its too cramped for 4 fish ). <Yes, that is far to cramped, but at least you realize that this fish need a larger tank.  As these fish get older they will get messier and messier. It will be a constant battle to keep the water clean and clear for the fish, which will take the fun out of having these fish.> about a week back, I was cleaning the tank as usual and siphoned off the water while cleaning the gravel. later on I realized that there were tiny fry swimming around in the siphoned water!! <wow.. congrats!  Must have been warmer water and activated their desire to spawn.> I could only save abt 10 of them as I did not find the rest :( they were about 4 days old when I found them, as per many websites and pictures. <many times the parents eat the young before people find the fry.  Yours were lucky to survive as long as they did.> now its been 6 days after I found them and all we r left with are 2 fry :( we were feeding them with Infusoria and baby food powder 3 times a day. we put them in the same tank in a net breeder. they seemed to be active when I feed them but we have been losing them at the rate of one per day!!! can u pls suggest what to do to save at least these two fry?? thanks for all the help :) <Fry are very hard to keep unless you are prepared for them.  Our goldfish fry had about a 50% survival rate.  Here is a great site to learn more about the goldfish you have.  http://www.goldfishinfo.com/spawn.htm#feedschedule  Check the rest of the site as well as links to learn more! good luck -Magnus>

Goldfish Gender Hello. I am just starting out for the first time with redcap goldfish. I have two, my question is which is female or male. I see no white spots on either, but the red part on one is just on top of its head and the other one the red part starts on its head and goes all the way down its face, is this a sign of their gender. Thanks for the info >>Hello :D To sex goldfish, you need to look at the gill covers. If any of your goldfish have breeding tubercles (white pimples) on the gill covers, those are the males. You will also see pimples along the edge of their pectoral fins. Females have a rounder body as it becomes filled with eggs (roe), and they also have a larger vent (wee wee area, LOL). -Gwen

Control of (pondfish) Breeding  Mr. Fenner: I read your article on fish spawning and it seems to be directed at the encouragement of reproduction, in a controlled way. We have bought a home recently and it has a lovely pond and we are learning to work with it, but we do not want to have too many fish. All of our animals (cats and dogs) are spayed and neutered and we feel strongly that we should not encourage reproduction of pets, in particular, the gold fish in the pond. I do not want to destroy the excess fish or dump them into ponds where their future is unknown or doubtful. Is there any way to control reproduction with food? I hesitate to suggest any chemical for the water, but any ideas? Donna Schmidt Wichita, Kansas. <Good question (at least for me thought-provoking and a challenge...). As far as I'm aware there is no food or environmental control of goldfish that one might use to prevent their engaging in reproductive behavior... You can try keeping out "floating plant material" that might serve to encourage their activity... but there is no way to sex them when small (so as to keep single sexes only)... or any other manner I'm familiar with... I encourage you to "trade out" offspring or give them to neighbors, children if you end up with excess young. Bob Fenner>

Swim Bladder Problem in Oranda Hello, we are new to the aquarium world. We have a 65 gallon tank that has a power filter and 2 undergravel filters. It has been established for about a month and a half. We have a black Oranda that has been in the tank for about a month. He has been fine except for the past week and half. He eats fine and interacts with the other fish fine but he spends a lot of time at the top. He tends to swim sideways sometimes and yesterday when I was watching from a distance he was laying at the top on his back. I thought he had died. Then I went over and he just swam to the bottom really fast. He has no visible signs of a problem, he always seems hungry. What do you suggest? Thanks Pam <Hi Pam, sounds like swim bladder problems, could be diet related.  I would add some frozen food and the occasional feeding of peas to the diet.  If this does not help, the addition of Epsom salt to the water might fix him.  If it still does not get better, he may need to be treated in a separate tank.  Take a read over the goldfish disease FAQs for more information, Best Regards, Gage. http://wetwebmedia.com/FWSubWebIndex/gldfshdisfaqs.htm  >     

Green Ranchu Problems <Hello! Ryan here> We have had 3 green Ranchu for just over 5 months now. We know we have a male a female but unsure of the other one! They have been fine, no problems until 2 days ago. The male & female have produced a white substance on their foreheads (on the male going down to his mouth). I know it's not the usual white pimple adults get - doesn't look anything like it. The other one seems fine (touch wood!). They are not spawning (have done twice before) or brushing against anything but do seem to be sucking air at the surface a lot of the time. They don't seem very interested in feeding either. Any help would be much appreciated. Regards Wendy <Wendy, it sounds to me that your fish may have a fungus.  Fungal infections are called Mycoses.  I would use a strong Malachite solution and watch carefully for secondary infections.  Some aquarium salt will help this from becoming a problem again in the future.  Use 2 grams per litre!  Good luck!  Ryan>

Goldfish age How old do goldfish need to be before having babies....and is there a way to tell the difference between male and female? Thank You for your help <Goldfish mature at around 1 year and hit their 'prime' at around 3 years. There are several ways to tell the difference between males and females, the males will get small white spots on their gills and pectoral fins, the males will have longer finnage, and when the female is growing eggs, she will get larger in the middle when viewed from above. There's a good page of info at http://www.calcna.ab.ca/~prsadlon/bre.html and also do a search at http://www.wetwebmedia.com for 'breeding goldfish'. You might also try this search on the web with your favorite search engine. Ronni>

Help (spawning goldfish) Hello, and thank you for your time. I have three goldfish in an aquarium together when I realized one of the goldfish were biting at the others fins.  <This happens... most often when they're too crowded... but sometimes due to nutritional deficiency, other times as part of spawning behavior> I removed her from the tank and put her in her own bowl. Soon after, she laid eggs, about 24 hours ago. My question is, can we put the male in the bowl now to fertilize the eggs?  <No my friend.> Will he? And is it too late?  <Yes, for this time (there will be others). One mechanism nature "provides" to prevent damage, disastrous genetic mixing is for fish eggs to "harden" (not accept sperm) a few minutes beyond being shed into the environment.> I did remove the female, but I don't know what to do now. Thanks again for your time. <Do study on re the spawning, rearing of these fish. It is a good idea you did separate them... as in this case their system might well have become so polluted that they may have perished. Please read here: http://www.wetwebmedia.com/PondSubWebIndex/pdfshbreeding.htm Bob Fenner>

Re: goldfish mating/breed problems Hello, I've had my 2 telescope goldfish for over a year now.  I just moved them to a 40 gallon tank from a 15 gallon. <good move> I've noticed differences in their behavior.  First off, I can't tell which one is male or female or if they're both one sex.   All they do all day long is chase each other around.  One is larger than the other one. The larger one is a deeper reddish gold color and the smaller is a light orange color with a white belly. I haven't noticed any of the signs of tubercles one either one of them.  They each seem to chase each other equally but it seems like they "take turns" when they chase.  I am concerned because when they slam each other into the walls I'm just worried they're hurting each other. Please email me back. Thanks for your assistance, <Could be that the larger redder one is a male and feeling a little frisky.  Or they could be trying to establish dominance in the new tank.  I doubt they will injure each other, but make sure there are no sharp decorations.  You could try removing the aggressor for a few days while the other gets settled in and then reintroduce them.> p.s. any advice on what species of fish I can add with my 2 goldfish would be greatly appreciated. <I would only add other wide bodied goldfish.  Best Regards, Gage More info on this topic can be found at the link below. http://wetwebmedia.com/FWSubWebIndex/goldfishfaqs.htm  >

Goldfish breed/ing I have a silver and orange gold fish I would like to no what breed it might be and also how do you tell if they are going to have babies. <chances are it is a comet goldfish, if you use google.com to search for goldfish you should find plenty of info and pictures to help with a positive ID.  You can tell if they are going to have babies by their behavior and color changes. -Gage> http://userpages.umbc.edu/~rrhudy1/gfish3.htm

Red lionhead goldfish Could you please tell me if this fish can breed on its own?  I just purchased one and it has been emitting trails of clearish, tube like string from it's butt and I was told by the pet store that it could be eggs.... Any help would be appreciated. Thank you. Becky <Yes, can do so. As you're likely aware, won't be fertile, hatch... Bob Fenner>

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Goldfish Success
What it takes to keep goldfish healthy long-term

by Robert (Bob) Fenner

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