Raising corydoras fry

[Karen B.]

Greetings!

I have tried a couple time to raise corydoras fry when I would see some eggs but each time, they would hatch and die within 24 hours.

I tried putting them in the fluval hang on breeding box (it pumps water from the main tank/water circulate a bit) but it didn’t work.

I tried putting them with my clown killifish fry in a glass container but they all died while the killies were thriving.

So I gave up, let nature do its work and I did end up with few fry and even eventually had to sell some as my 20 gallons was getting overcrowded. 

Now I updated to a 30 gallons and would like to have few more (currently have 8). The problem is that since I added my 2 females honey gourami, no fry ever survive.

Yesterday I was cleaning the tank and was astonished at how many eggs there was. I am about to label that tank 18+ so much these corydoras are having fun… 😅

I decided to try one last time and see if I could raise some. I had bought the Ziss fish breeding box for another purpose but I figured out I could try it - lots of water circulation and the box is actually inside the tank. My only problem is that the bottom is made out of mesh.

I was afraid the eggs or the fry would go through so I came up with the idea of putting a glass container inside the box. The problem is that the fry swim out of it as soon as they hatch.

At least now I know they won’t fall through. But I am afraid the mesh might hurt them when they swim/search around for food? It’s not sharp or anything tho.

And there is the food. It won’t stay in or will it? I feed them fine powder food like Hikari first bite.

[Guppysnail]

I’ve tried repeatedly with different breeder boxes/specimen containers and air stones. No luck. A few days ago I pulled eggs (my pleco eats them in tank) and threw the anacharis they were on the the snail tank to float. They either hatched or the baby pleco in there swam u and are them. We will see. I’m really thinking the key is micro fauna we cannot see as first foods are a must for these guys. 

[Tihshho]

It looks like a few of those eggs (white ones) are not fertile. Making sure to pull unfertilized eggs will help reduce the chance of fungus on the eggs. Years ago I would place the eggs in a hatching tank that was heated with a bit of methylene blue and stick the eggs to the front of the glass of the hatching tank. Once they hatched I would pull the fry and move them into a rearing tank. 

Per what I've seen others do over the years is hatch the eggs in a specimin container rather than dedicating a tank. They would hang the specimin container in the parents tank to stabilize temps and do daily water changes with tank water into the specimin container to keep up with water quality. Once the eggs hatch, there isn't a need to keep up with methylene blue, it's only used to combat/prevent fungus. 

Once I get my Sterbai's and Apisdoras breeding I plan on trying my current hatching method for egg scatterers which involves a floating breeder box with neocardina shrimp in there. Neo's don't eat healthy eggs, but will pick them up and clean them. They also eat bad eggs so I don't have to go through and pluck out bad eggs to curb possible fungus. So far it's working great with any Ancistrus eggs I've artifically hatched as well as the Ricefish eggs I pull. 

[Dancing Matt]

I have raised them in a specimen container but I don't see why what you have would be a problem. I put some Christmas moss in with them and fed them powdered repashy and live baby brine (now I see a potential problem with the mesh...). I am not sure if they were eating BBS right away but within... a week? I was seeing golden brine bellies. I also ended up putting in repashy blocks, maybe you could put a smaller container in there and put the food in the container?

[mountaintoppufferkeeper]

I have done sterbai eggs in the ziss box. I prefer it for corys over the other styles of breeder box; id suggest adding live moss etc from the main tank in there when they hatch for the micro foods and cover it provides them. 

I do like the mesh bottom since its that much more water flow and i dont need to worry about temp fluctuations or water quality quite as much as other methods. They other bonus is any food the fry dont eat generally falls through. They get a little gunky at 7 days or so and i siphon the mesh with an airline tube. 

I just roll the eggs from the tank side where layed to my gloved finger and to the inside of the box. They were spaced enough that the fungus didnt spread from the few that did fungus.  They cory fry will normally sit on that plastic edge in mine. 

I have the box in a 50 gallon. I normally feed the box standard food this is extreme flake, they also have done repashy in the box and live baby brine. The brine will fall through the mesh and feed the rest of the tank. Im sure its possible that they could have a freak accident but i personally think this box is excellent for my fry. If i do methelyne blue i use a specimine container hung in the tank with a slow bubbling rigid airline to break surface tension. Sterbai fry F2

 

i also use the boxes to raise batches of mekong puffer fry. Normaly they stay in them to 24 days with no issues before moving to a grow out tank. 

F1 puffer fry

Tonights pull day 0 F1 Pao cf palustris

[nabokovfan87]

On 5/16/2022 at 12:55 PM, Guppysnail said:

They either hatched or the baby pleco in there swam u and are them. We will see. I’m really thinking the key is micro fauna we cannot see as first foods are a must for these guys. 

Mulm absolutely helps. In my first successful spawn I had moss balls with mulm, rocks for them to hide in.  The fry can be incredibly smart. Prior to that point, I would think something like the Co-op baby fry food or repashy powder would work just fine in a breeder box scenario.

 

 

On 5/17/2022 at 8:42 PM, mountaintoppufferkeeper said:

I have done sterbai eggs in the ziss box. I prefer it for corys over the other styles of breeder box; id suggest adding live moss etc from the main tank in there when they hatch for the micro foods and cover it provides them. 

I do like the mesh bottom since its that much more water flow and i dont need to worry about temp fluctuations or water quality quite as much as other methods. They other bonus is any food the fry dont eat generally falls through. They get a little gunky at 7 days or so and i siphon the mesh with an airline tube. 

I know some use a turkey baster to siphon out fry boxes too!  Have you tried the ziss egg tumbler?

[mountaintoppufferkeeper]

On 5/18/2022 at 12:51 AM, nabokovfan87 said:

Mulm absolutely helps. In my first successful spawn I had moss balls with mulm, rocks for them to hide in.  The fry can be incredibly smart. Prior to that point, I would think something like the Co-op baby fry food or repashy powder would work just fine in a breeder box scenario.

 

 

I know some use a turkey baster to siphon out fry boxes too!  Have you tried the ziss egg tumbler?

Im a big mulm fan. I have a ziss tumbler and a few others but havent quite mastered tumbling eggs.  If I dont do the breeder box i normally do a 3/4 full specimine container with a drop of methelyne blue,  hung inside the tank with rigid airline bubbling enough to break surface tension and flow over the eggs if its needed for a species. That works for my setup if its a species that gets fungus on fertile eggs that tends to mitigate it for me. 

[Dancing Matt]

On 5/17/2022 at 9:42 PM, mountaintoppufferkeeper said:

I do like the mesh bottom since its that much more water flow and i dont need to worry about temp fluctuations or water quality quite as much as other methods. They other bonus is any food the fry dont eat generally falls through. They get a little gunky at 7 days or so and i siphon the mesh with an airline tube. 

I have the box in a 50 gallon. I normally feed the box standard food this is extreme flake, they also have done repashy in the box and live baby brine.

 

Great to know most fry foods don't fall through. I never thought about how beneficial flake food could be in this instance.

[mountaintoppufferkeeper]

Some food does go through for sure but those edges collect a bit and the other fish eat whatever goes through. Flake works well for my sterbai fry but they also eat anything edible  in there