# Cory breeding!



## Costa (5 Nov 2017)

Hey guys,

I'm reading up a lot on Corydoras breeding because my wife likes them and that's a great way for me to get more tanks!!

So I bumped into this German forum (corydorasforum.de) and what the users seem to say (my German is a bit rusty) is that the breeding tank should have 0.5-1.0cm of sand and only around 3cm of water, which I find to be very shallow, at least compared to the many videos and how-to's I've watched and read.

Could any seasoned Cory breeders comment, please? Thank you and wish you all a relaxing Sunday.


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## GHNelson (5 Nov 2017)

Hi
I've found that Corys tend to go into breeding mode after large water changes....could be induced by the slight temperature difference and the fresh/clean water!
hoggie


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## Costa (5 Nov 2017)

Thank you Hoggie, this is what I've been reading as well. Do you have any comments re the water level inside the tank that will be housing the Corys?


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## GHNelson (5 Nov 2017)

Hi Costa
I have noticed that if you lower the water level to say a 10 to 12 inch depth for a period, then add the fresh this may be one of the breeding triggers!
hoggie


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## KipperSarnie (5 Nov 2017)

About a year ago I bought 6 Sterbai for my 2ft deep discus tank, I now have at least 21 of various sizes!  Every time I clean the filter there are a couple of juveniles in there.
Water changes simulate fresh rains in The Andes, not only is the water parameters different but also there is an increase in available food.


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## GHNelson (5 Nov 2017)

Lost my last female Sterbai a couple of days ago, she was a old lady 18 years old.


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## Edvet (5 Nov 2017)

Old trick is to do waterchanges but keep the old tank water and let it cool, then put it back.


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## zozo (5 Nov 2017)

I'm no breeder, but red somewhere a tut.. next to a good healthy diet, i guess in any case tha's always life food... Keep 'm for a while in a half drained tank in shallow water, than simulate flood season, in this rainy season everything cools and the falling rain earates the water, this seems to trigger the Cory's to spawn.. Gradualy lower temperatur, to 19°C with adding cooler water over sprinkle installation that simulates rain and flooding.. 

No personal experience, as said i once red it as tutorial from a Cory breeder..

Also did read that lowering temp already triggers cory's to spawn.


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## Costa (5 Nov 2017)

Thank you all for the tips! Hoggie sorry for your loss. I've had 5-6 pandas for a year in a 30gal tetra tank. They never bred (well, I never got any offsprings at least) but I got several ember tetra babies that still live to this day. Ever since I moved everything to the 230gal, I had no baby fish, don't know why...

Edvet, what's the point of reusing the old water?

Thanks again!


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## Edvet (5 Nov 2017)

Doing a large waterchange without changing the waterchemistry, as i said it's an old trick. I wouldn't mind changing it nowadays. But if you need to do a lot of work to get good water ( for instance if you have very hard water and soft water cory's) this can help doing a large change easily.


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## Costa (5 Nov 2017)

Right, understood, thank you Edvet.

@hogan53 Hoggie have you found some types of sand to work better than others? If it matters, I have relatively hard water (GH in the 10 range). Which type/brand would you recommend?


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## GHNelson (5 Nov 2017)

Sand is not a necessity...Corys will breed in most tanks with different substrates!
The Female and Male must get into the T position or the eggs will not be fertilized!


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## Costa (5 Nov 2017)

Thank you! I'm debating whether I should move the corys I've got from the tank they are sharing with 60 or so tetras to a new tank, or just go to the LFS and get some new corys. Can the LFS staff tell male from female? My wife wants pandas, I prefer sterbai.


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## GHNelson (5 Nov 2017)

I don't think you can distinguish between the Male and Female gender at the juvenile stage!
I could be wrong though.....Tetras will eat eggs and young fry if given the opportunity!
If you have a very heavily planted tank, the offspring may have a higher percentage to surviving to adulthood!
Cheers
hoggie


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## AverageWhiteBloke (5 Nov 2017)

KipperSarnie said:


> Every time I clean the filter there are a couple of juveniles in there.



Just reminded me to check my filters when cleaning.


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## BubblingUnder (5 Nov 2017)

Costa said:


> the breeding tank should have 0.5-1.0cm of sand and only around 3cm of water, which I find to be very shallow


Mine spawned in my 125L display aquarium on a (Ludwigia palustris green) stem plant this is a deep aquarium. I just put the eggs in a floating plastic milk bottle in the 125L display tank (so this is the shallow water) & change the water in the bottle twice daily from the display tank when I feed.


Costa said:


> whether I should move the corys I've got from the tank they are sharing with 60 or so tetras to a new tank, or just go to the LFS and get some new corys.


You should probably try to ensure that your breeding stock comes from separate sources (including some 'wild' if possible) to keep the genetics ok.

I've got some C.Sterbai on the go at the moment (I'm on my 4th batch) its a bit of an uphill struggle & my parent Sterbai are not big so not many eggs are spawned. I'm still learning but getting better with each batch.....

1st batch - 1 fry survived
2nd batch - 2 fry survived
3rd batch - 9 fry survived
4th batch - 6 fry survived

Good luck with yours...


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## Costa (5 Nov 2017)

Thanks @BubblingUnder ! Do you have your sterbai breeding pair in a separate tank, or together with other fish? I am reading that catapa/oak leaves help a lot with protecting the fry and adding helpful tannins to the water column. Would be interested to know what your set up is.


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## BubblingUnder (5 Nov 2017)

Costa said:


> Thanks @BubblingUnder ! Do you have your sterbai breeding pair in a separate tank, or together with other fish? I am reading that catapa/oak leaves help a lot with protecting the fry and adding helpful tannins to the water column. Would be interested to know what your set up is.


I have nine breeding size C.Sterbai within a community aquarium (containing a Discus,Otto's,Cardinal Tetras & Ammano shrimp). Tannins are provided by a piece of bogwood within the tank (I've not tried leaves myself). I have put my setup as a journal on UKAPS https://www.ukaps.org/forum/threads/amazon-type-planted-125l-tank.49265/ hope this is helpful to you.


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## Costa (5 Nov 2017)

Very helpful thanks again @BubblingUnder - very surprised you had several cory eggs and fry escape the cardinals and the other corys!


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## BubblingUnder (5 Nov 2017)

Costa said:


> very surprised you had several cory eggs and fry escape the cardinals and the other corys!


They will eat them if they get the chance so you would need to remove them (about a day after they were laid worked for me) I used scissors to remove the stem plant leaves they had spawned on & moved them to the floating plastic container to avoid that. Also if you overfeed all the other fish it seems to decrease their interest in eating the eggs.


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## Parablennius (6 Nov 2017)

Well, this is very timely.
Yesterdays water change 30% but cooler than the tank, so dropped around 3 deg. Later that day a pair of Sterbai's, out of six, start the T shaped ritual. This morning my Oto's, 1 male 3 females, are spawning on the jungle Val.
I remember from my amphibian exploits, accounts of captive breeding certain frog species being stimulated to spawn after a cold shower! Just chucked a Beech leaf into a plastic tub floating in the tank, thought I might as well. Takes you back to being a kid and watching Guppies being born for the first time, you never lose it!


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## mort (7 Nov 2017)

Costa said:


> Hey guys,
> 
> I'm reading up a lot on Corydoras breeding because my wife likes them and that's a great way for me to get more tanks!!
> 
> ...



The low water depth from my understanding simulates the shallow water environment some cories breed in. They do this at the edge of rivers where the water is only a few inches deep. This is with species that bury their eggs in the sand and with these you need a shallow depth as deeper water can cause too much pressure on the baby cories so they don't develop properly and can die. I've not come across recommendations for that shallow but 4" or so can be suitable for some. Most however will be fine in normal tank depths.

I also use cooler water changes to evoke breeding but most cories prefer to breed at night so you might not see it and cories don't have any parental care and will happily eat them, so another reason you might not see many fry. Either provide shelter (java moss is great) of remove the eggs (you could remove the parents but it might put them of spawning in the future).


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## BubblingUnder (8 Nov 2017)

mort said:


> low water depth from my understanding simulates the shallow water environment some cories breed in. They do this at the edge of rivers where the water is only a few inches deep. This is with species that bury their eggs in the sand and with these you need a shallow depth as deeper water can cause too much pressure on the baby cories


I too read reports from collectors in the wild about some species of Corys burying their eggs under sand in shallow water I wouldn't have thought that this would be due to atmospheric pressure as they don't have any airspace within them (unlike human divers who notice pressure due to the air space within their bodies ears,lungs etc.).
The trigger for spawning is a flood so it would make sense to spawn as close to the waters edge as possible to allow the fry to:

1) Access new unexploited food sources in the flooded area.
2) Greater oxygen availablity in shallow areas.
3) Less predation as the number of aquatic predators falls per square meter with turbid water & cover from leaves/branches.
4) Less current to sweep the fry away.

Interesting to speculate though isn't it.


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## Edvet (8 Nov 2017)

BubblingUnder said:


> as they don't have any airspace within them


swimbladder?


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## BubblingUnder (8 Nov 2017)

Edvet said:


> swimbladder?


Your absolutely right I realised after I posted. So perhaps they can't reach the surface in deep water if their swim bladder is not fully developed (as I see my Cory fry do occasionally).


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## roadmaster (8 Nov 2017)

I was told By a fellow that called himself coryologist, that shallow water was easier for the cory's to get back in forth to the surface while the organ that allows them to expel and gulp air develops further at such a young age.
Just sayin


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## mow said (8 Nov 2017)

I bred bronze corydoras this year I have few images  that might help. After they laid eggs what I did was use my fingers to remove the eggs and place them into my shrimp tank. If you don't remove the eggs they will be eaten by the Corydora's. And also the eggs are easy to get fungus I made sure they were next to the filter outtake so that no fungus builds on them.After three days the babies hatched and one by one i used syringe to put them in a container from my shrimp tank ,the shrimp tank was too deep for them to gulp air . I placed around 200 babies into a food container this was 2 weeks of laying eggs every 3 days. After three days the babies yolk disappears and you need to start feeding them I find the best food to feed at this time is micro worms. Water changes 3 times a day you will have allot of deaths but don't worry as those are the weak ones. Keeps feeding and doing water changes i ended up with 20 if I had an extra tank I reckon I could of ended up with more. After they were grown up I transferred them to the shrimp tank this was a month later and continued to feed micro worms. They all grew within 3-4 months sold all of them as I didn't have any room . Its not easy process you have to be dedicated to do allot of water changes and feed 3 times a day.


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## Costa (8 Nov 2017)

Thank you very much @mow said

I have 2 adult bronze corys (which both look very plum, so probably females) and 2 young pandas (can't tell the sex). I started with 5 pandas which I had just bought from a store and had shipped overnight, but 3 of them died (turned pale white and died the next day). I don't know what caused it. I haven't seen any intercourse going on between them.

That said, the corys are in a community 650L tank with another 60 or so tetras. So that might be why I haven't seen any cory eggs - but I'm very curious as to why they don't spawn at all...

Thanks again! Congrats on the baby corys.


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## mow said (8 Nov 2017)

Thats is one of my Corydora's females holding her eggs.


 You need to put more corys in there. Mine were 5-7 cm big and its not easy to sex corys you have to look up to see which one is a male or female.I had mine with silver tip tetras and they are one of the most aggressive tetras and they laid allot of eggs. I had 6 in total they were laying eggs every month atleast twice. Get 6 pandas and 6 bronze make sure they are adults atleast 5-6 cm and do your normal waterchanges but slightly colder water and they will breed.


 
Hence why I sold all my corys they were digging up my new tank allot.


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## mort (9 Nov 2017)

I saw a video recently where a corydoras specialist said that it's not the size of the cory that determines if it's able to breed but the age. Apparently some species take a long time, 6-7 years, before they mature and spawn. Size has nothing to do with age after a point so young well fed fish might still need time.
I don't think this is the case for more commonly seen species like bronze, panda or the commercially bred ones but give them a lot of time before you start worrying.

It was quite an interesting talk if you have a spare hour. I'll try and remember to link it tonight.


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## Costa (9 Nov 2017)

5-6cm isn't too big for corys? Thank you


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## BubblingUnder (9 Nov 2017)

mort said:


> quite an interesting talk


I think you might mean "How to breed Corydoras Eric Bodrock's talk at Cataclysm 2017" 
An excellent presentation. The part about age being more important than size is near the end of the presentation (about 55 minutes in) but the whole talk is brilliant.


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## mort (9 Nov 2017)

BubblingUnder said:


> I think you might mean "How to breed Corydoras Eric Bodrock's talk at Cataclysm 2017"
> An excellent presentation. The part about age being more important than size is near the end of the presentation (about 55 minutes in) but the whole talk is brilliant.




Yeah that's the one, watched it over the last couple of days. Thought it was very interesting especially the bit about leaf litter depth in nature.


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## mow said (9 Nov 2017)

Costa said:


> 5-6cm isn't too big for corys? Thank you


depends bronze corys grow to 7.5 cm dunno about others


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## mow said (9 Nov 2017)

mort said:


> I saw a video recently where a corydoras specialist said that it's not the size of the cory that determines if it's able to breed but the age. Apparently some species take a long time, 6-7 years, before they mature and spawn. Size has nothing to do with age after a point so young well fed fish might still need time.
> I don't think this is the case for more commonly seen species like bronze, panda or the commercially bred ones but give them a lot of time before you start worrying.
> 
> It was quite an interesting talk if you have a spare hour. I'll try and remember to link it tonight.


I agree with you its age but when buying from a petstore you don't exactly know their age so it's better to guess with measuring their size as i said bronze cory would be 5-7 cm and they should be ready to start breed.


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## Costa (28 Nov 2017)

Thank you all, just finished building a new tank (45*30*30cm) for my Corys. I am getting them from the LFS tomorrow and will post pictures.


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