Corydoras breeding

[VanDogh]

I've had my corys spawning before and unfortunately none of the fry survived. Either way, everytime they do the deed, their eggs get eaten almost instantaneously by my gluttenous kerri tetras and blue gouramies, I am never fast enough to remove the egg in time. I also can't sit and wait all day for my corys spawning that I am prepared to catch any egg at any given time. Now, how do I get around this problem? Do spawning mops work? I would move them to another tank but all of my other tanks have gravel unfortunately. Is it possible to make them spawn in a big, 33L plastic container like This one?

[Kunersbettas]

What species are they? I have some old books from the controversial Axelrod that talk about corydora breeding.

[VanDogh]

@Kunersbettas venezuelanus  🙂

[Kunersbettas]

Couldn't find anything specific in the books by Axelrod. Really awesome looking fish though, never seen them before! I think most corydoras lay their eggs on the sides of the tank. According to Axelrod, 

"Corydoras are bred as follows. It is most important that the breeders large enough and old enough. The aquarium should be of at least 40 liter capacity. The bottom should be covered with well-washed gravel. A few clean Cryptocoryne plants will give the breeders more security. Breeders should placed in the spawning tank at night and, if in condition, will spawn the following morning. If spawning is not accomplished in 48 hours, change breeders. Eggs will be placed on the plant leaves or sides of the aquarium and will number two to three hundred. While it is true the parents do not show any further interest in the eggs and usually will not eat them, it is best to remove the parents immediately after spawning. After this is done add methylene blue to the tank. Raise the young in the breeding tank. The eggs hatch in five days and the yield is never more than 30 or 40% of the eggs laid Why there is such a consistent number of infertile eggs has never been satisfactorily explained. The young are large enough to take brine shrimp and microworms immediately. 7.4 pH and medium soft brown water yield best results."

-Axelrod, Exotic Tropical Fishes, Expanded Edition, 1996.

Keep in mind that this information may be outdated. Most people don't encourage the use of Methylene Blue anymore. Please note that these are his "commercial breeding techniques". Hope this does something to help and isn't redundant information.

[VanDogh]

@Kunersbettas

Thank you! This was still helpful 🙂  I've seen a couple of people use methylene blue and I am pretty new to this hobby, is there a reason why it is considered outdated? 

[Kunersbettas]

I think either it is considered somewhat harmful to dispose of, or not as natural of a chemical as other alternatives.

[VanDogh]

On 5/28/2024 at 1:36 AM, Kunersbettas said:

I think either it is considered somewhat harmful to dispose of, or not as natural of a chemical as other alternatives.

I see, what other better alternatives exists? 🙂

[Kunersbettas]

I don't know what is used as a substitute. I think you will be fine using it. I think it is only discouraged by some because people use it for medical purposes. With fish though, it aids their breathing, which is vital for young fry. You can't overdose the fry on it easily.

[Cinnebuns]

Spawning mops do work however some will use them more than others. My pandas almost exclusively use the mops whereas my paleatus cories use them about 25% of the time. It can be a risk to breed out of a community tank but it's possible. I would advise raising the fry in a seperate tank once you are successful pulling the eggs. Do be aware, although a spawning mop can increase your chances of the eggs surviving, the tetras may get wise and swim into the mops to eat them. It's hard to say. Either way it will give you a better chance. 

[JE47]

For helping prevent fungal growth you can use aside from methylene blue you could use Indian almond leaves or 4% food grade Hydrogen Peroxide which I have used before. I wouldn't say that methylene blue is necessarily an outdated practice but if you where to say want to use a more natural fungal deterrent than Almond leaves are the way to go.