Bronze Corydoras Eggs

[lawrencezarb]

I am having no success with my Bronze Corydoras eggs.
 
I have many batches of eggs from the parents in a separate breeding tank, and used serveral adults, but none of the eggs ever seems to be dertile, they stay white and eventually fungus.
 
What am I doing wrong?

 

[eaglesaquarium]

Well, what are you doing?   Are you conditioning them to breed with lots and lots of high protein food and cold water changes?  Or are they just doing this on their own?
 
 
 
Are you certain that you have sufficient males to fertilize?  The standard ratio is 2m:1f.

 

[lawrencezarb]

Hi, In my breeding tank I have 2 males and 1 female.
 
I can "induce" them to breed by adding cooler water, but they sometimes breed on their own accord.
 
As for the food, I do not make too much effect on that ppart, basically feeding them mainly tablet food. Could this be the problem, do they really need lots of high protein food?

 

[fluttermoth]

Do you use any kind of filtration or airstone in the breeding tank? Lack of water movement might be a contributing factor.
 
You could also try adding methylene blue to the breeding tank, when you first move the eggs; it'll have denatured enough by the time the eggs hatch to not harm the fry.
 
And how are you moving the eggs? Are you leaving them enough time to harden slightly?

 

[lawrencezarb]

I have a fluval 1 internal filter in the tank.
 
It's not a case of the eggs fungusing, as I have prevented that using  methylene blue, the issue is the eggs are not fertile.
 
When I move the eggs I use a razor blade.
 
I have tried leaving the eggs where they are and segragating the adults, but still no fertile eggs

 

[fluttermoth]

There must be a fertility problem with your fish then.
 
You could try feeding a more varied diet, as eagle suggests and see if that helps at all.
 
Oh; have you checked the pH and hardness of your water?

 

[lawrencezarb]

No, I have not check PH or hardness.
 
What should I aim for?
 
As for food, I understand frozen bloodworm is good, should I feed them that solely?

 

[eaglesaquarium]

Cories prefer soft and acidic water.  The softer the water, the better for breeding.  Also, a pH of about 6.0 or so would be best.

 

[lawrencezarb]

Does the softness and Ph affect the viability of the eggs?

 

[fluttermoth]

I'm not 100% about bronze cories (never kept them myself), but it does in some fish, so it could be worth checking out.

 

[eaglesaquarium]

I think it affects the fish's interest in breeding more than anything.  
 
http/www.planetcatfish.com/shanesworld/shanesworld.php?article_id=312
 
This link might be more help.

 

[lawrencezarb]

Thats the thing really. I have absolutely no problem getting them to breed and produce the eggs, its just getting fertile eggs that is the issue.!

 

[snazy]

Thats the thing really. I have absolutely no problem getting them to breed and produce the eggs, its just getting fertile eggs that is the issue.!

 
When my corys were young they seemed to produce a lot of infertile eggs. That changes in time. Just keep trying.
If the eggs are infertile, they turn white pretty fast, within 24 hours and don't even have time to get fungus on them by then.
For the record, my corys are in pretty hard water and spawn constantly without any triggers or cold water changes. The hatch rate of the eggs isn't 100% but with the frequency and amount of eggs one can collect really doesn't make that an issue unless you want to breed mass amounts.  The problem is where to raise so many corys
Good luck.

 

[mtbdean]

I keep my Cory's in a Community aquarium, Bronze + Albino's with 1m2F, with a temp of 25c, PH 7.5 (Tapwater) with quite hard water.
 
When I do a water change, i change with cooler water (Around 20c,) with a 40% change, this drops down to around 22c and you can be guaranteed that there will be eggs everywhere the next morning.
 
I basically pull mine off with a razor blade, drop into a breeder net with a powerful air bar, that circulates the water contantly, aswell as being infront of the spray bar from a 306, at the moment, ive got 7-8 Albinos that are 1-2cm and 1 single Bronze Cory thats now the size of 3-4cm
 
Cheers

 

[DoubleDutch]

Cories prefer soft and acidic water.  The softer the water, the better for breeding.  Also, a pH of about 6.0 or so would be best.

 
That's not exactly right for all species of the about 1500 known ones. Bronze are very tollerate to PH (6 is very low for them) and temperature. For instance for habrosus you are right !!! Mine will spawn after waterchanges and low pressure weather, tap is Ph 7,2 and bred the young ones in a unheated tank 18-24 C. Think the male isn't able to fertilize the eggs  in one way or another. You are sure there is one male?
 
Greetz Aad