Breeding Pygmy Corydoras

[Devilish]

Hello all! I've been keeping pygmy corydoras for a few years because they are my favorite fish. I'd really like to see them reproduce but they don't seem to be doing so on their own. So what I'll do here is go through some of the steps I've been taking to get them to spawn and hopefully one of you fish experts can help me theorize a way to make the reproduction happen!

so in the beginning I had my pygmy corys in a 20 gallon community tank. This is how they lived for the last few years. I began to believe some of the other occupants were bullying them away from food and otherwise making them uncomfortable so I moved the corys to a tank I found in an alleyway. The tank appears to be 5-10 gallons, I can't be sure. The group of corys is 20 strong and there are only pygmy corydoras in the tank. I know that may seem a bit overstocked but I've been monitoring the water chemistry and it stays really clean and has plenty of plants to help clean the water. I've also been doing regular water changes. The fish have plenty of space and seem happy and social.

I feed my corys frozen daphnia twice daily and occasionally use a sinking algae wafer to balance their diet. I do a 40% water change every day (for the last few days) with slightly colder water to induce mating. Still nothing. I am considering getting a grindal worm culture so I can feed them live foods but live baby brine shrimp have not worked in the past.

So with all that in mind (it's a lot, sorry) I would love to hear some suggestions on what might change my luck. Thanks for reading

 

[betta4ever!]

Τhe tank looks way too small imo. What are the dimensions?

 

[Devilish]

Τhe tank looks way too small imo. What are the dimensions?

I couldn't say, I never measured it. I can say it is a bit tall, I'd rather have it long

I don't think the size of the tank is the issue. When I started the 20 gallon community tank there was a long span of time where it was only cherry shrimp and pygmy corydoras. They still did not breed

 

[Byron]

The tank size is not a problem here. I would however suggest two additions...floating plants (more, fill the surface to shade the tank) and dried leaves. You are in NA and autumn is with us, so go to a safe site and collect fallen leaves from hardwood trees like oak, maple, beech, popular. Leaves that have fallen will be dead dry (no sap). Lay them out, rinse them in cool water (not in hot or boiling water), lay them out on clean paper towels to dry. Store them in a plastic bag or container, whatever. Put half a dozen in the tank, they will initially float but within a few days begin to sink, and lay them around the substrate. The more the better, but start them now, as you want these especially for the fry. Dried leaves produce loads of infusoria as they begin to break down, and this is the absolute best first food of all fish, esp cories. My tank of pygmies spawned over several years continually, and grew on this food alone.

The moss is excellent, you will in time find eggs stuck in the moss clumps as well as on the tank glass, wood, etc. This species is not bad for eating the eggs and some will survive if the pygmies are the only fish. Small snails are OK, but no shrimp. I'll add a photo of my 10g home of my pygmies, that grew from the initial six to over 30 in a couple years. Stuffed with leaves, and second phot is one of the parent females with fry of two different spawns.

Food. Daphnia is excellent. Forget the algae wafers, cories cannot digest plant stuff so these will be more harm than good here. Shrimp is good, I always used Omega One Shrimp Pellets. The other absolute food is Fluval Bug Bites, the mini (smallest) size. Add a few, stir them to make them rapidly sink. In their habitat, all cories feed primarily on insects and insect larvae, then crustaceans. Few if any worms. Bug Bites and daphnia and shrimp are your best foods. Forget live foods, waste of energy with this species.

Water Parameters. The softer the better. What is the GH and pH?

 

[Devilish]

The tank size is not a problem here. I would however suggest two additions...floating plants (more, fill the surface to shade the tank) and dried leaves. You are in NA and autumn is with us, so go to a safe site and collect fallen leaves from hardwood trees like oak, maple, beech, popular. Leaves that have fallen will be dead dry (no sap). Lay them out, rinse them in cool water (not in hot or boiling water), lay them out on clean paper towels to dry. Store them in a plastic bag or container, whatever. Put half a dozen in the tank, they will initially float but within a few days begin to sink, and lay them around the substrate. The more the better, but start them now, as you want these especially for the fry. Dried leaves produce loads of infusoria as they begin to break down, and this is the absolute best first food of all fish, esp cories. My tank of pygmies spawned over several years continually, and grew on this food alone.

The moss is excellent, you will in time find eggs stuck in the moss clumps as well as on the tank glass, wood, etc. This species is not bad for eating the eggs and some will survive if the pygmies are the only fish. Small snails are OK, but no shrimp. I'll add a photo of my 10g home of my pygmies, that grew from the initial six to over 30 in a couple years. Stuffed with leaves, and second phot is one of the parent females with fry of two different spawns.

Food. Daphnia is excellent. Forget the algae wafers, cories cannot digest plant stuff so these will be more harm than good here. Shrimp is good, I always used Omega One Shrimp Pellets. The other absolute food is Fluval Bug Bites, the mini (smallest) size. Add a few, stir them to make them rapidly sink. In their habitat, all cories feed primarily on insects and insect larvae, then crustaceans. Few if any worms. Bug Bites and daphnia and shrimp are your best foods. Forget live foods, waste of energy with this species.

Water Parameters. The softer the better. What is the GH and pH?

Thanks for the advice!

Are regular leaves just as good as good as the ones they sell at fish shops (almond leaves and the like)? I had never considered this.

The water Ph is very low. It's around 6 to 6.5 which I'm led to believe is best for breeding. The hardness is one thing I could take a closer look at. I don't remember the numbers from last time I checked but one level is at the highest and the other is at the lowest (gh and kh I believe). Is there a way to adjust the water hardness?

 

[Byron]

Are regular leaves just as good as good as the ones they sell at fish shops (almond leaves and the like)? I had never considered this.

Yes, provided the leaves are from hardwood trees, and are dead dry. I especially like oak leaves, and I had a tree in my backyard so I knew it was safe (never used pesticides, fertilizers, chemicals of any sort). I also used maple.

The water Ph is very low. It's around 6 to 6.5 which I'm led to believe is best for breeding. The hardness is one thing I could take a closer look at. I don't remember the numbers from last time I checked but one level is at the highest and the other is at the lowest (gh and kh I believe). Is there a way to adjust the water hardness?

Let's get the GH pinned down. KH doesn't matter here, and your pH is ideal in the acidic range. Mine happened to be down around 4 or 5.

 

[Byron]

One other thing, forgot to ask earlier...what temperature is the tank water?

 

[Devilish]

One other thing, forgot to ask earlier...what temperature is the tank water?

It sits at 72°F without a heater. The lowest the corydoras will be comfortable at I believe. I'm considering getting a heater so that when I change the water with something cooler it won't be too cold for my fish. When I do change the water it gets no colder than 68° F for a few hours

 

[Byron]

It sits at 72°F without a heater. The lowest the corydoras will be comfortable at I believe. I'm considering getting a heater so that when I change the water with something cooler it won't be too cold for my fish. When I do change the water it gets no colder than 68° F for a few hours

I would not have a temperature difference this much. Optimum temperature for this species is in the range of 22-25C/72-77F. Water changes should have water that is within one or two degrees of the normal temperature.