General question regarding Corydoras paleatus fry

DuchessNeeka

So when I started my 55 gallon tank, I did a small school of 5 Corydoras. A few months ago, a 6th seemed to appear into the group - he's a longfin so he is definitely more distinctive than the others (we call him Aquaman) so I knew my Corydoras were breeding. I've now found a 7th younger in the big tank while pulling Corydoras eggs to put into a nursery just to see if I could hatch a few.

I got through the hatching and ended up with 7 fry out of about 15-ish eggs (My Angelfish saw the eggs as a snack so she took out most of them). They finished hatching around 5PM on Tuesday (6/21). I currently have them in a 2.5 gallon that I had sitting around. I'm using an xs filter with a bit of pantyhose covering the slots so that the fry aren't sucked up into it. I'm also doing a small water change at the end of each day where clean up the bottom of the tank and pull out a little of the water, send it back to my 55 gallon, and then use water coming from the filter on my 55 gallon to replace into the nursery tank. Its bare bottom, I do have a little java moss in there for security and hiding and all those nice things that babies like that came from my big tank and a couple snails just for cleanup assistance.

My question: How do I know my fry are eating? I'm pretty limited when it comes to magnification to get super close looks at them I've been using my cell with zoom with the best clarity to try to look at their bellies. I'm just not sure if they're eating yet. I am using Hikari First Bites. I take a little water from the tank into a tiny cup thing and dip a dry chopstick into the powder then stir it into the water. I let that sit for a couple of minutes then try to distribute the food out across the entirety of the small area of the 2.5 gallon.

I'm just not sure if they're eating. They're not overtly active currently. I guessed its because they're like 3 days old now. I'm generally just worried about keeping them alive. I am doing about 4 small feedings per day and my end of day is when I do the cleaning to clean up as much of the bottom as I can and water change. I've read a lot on the subject my concern now is just them eating.

I'd like to have them live and use them in a 29 gallon tank that I'm setting up for shrimp just because I think a shrimp colony would be cool to watch.

If anyone with experience has any information on what I should look for or how long it may take before I can observe what its like "typical" behavior - that would be awesome.
 

SparkyJones

So when I started my 55 gallon tank, I did a small school of 5 Corydoras. A few months ago, a 6th seemed to appear into the group - he's a longfin so he is definitely more distinctive than the others (we call him Aquaman) so I knew my Corydoras were breeding. I've now found a 7th younger in the big tank while pulling Corydoras eggs to put into a nursery just to see if I could hatch a few.

I got through the hatching and ended up with 7 fry out of about 15-ish eggs (My Angelfish saw the eggs as a snack so she took out most of them). They finished hatching around 5PM on Tuesday (6/21). I currently have them in a 2.5 gallon that I had sitting around. I'm using an xs filter with a bit of pantyhose covering the slots so that the fry aren't sucked up into it. I'm also doing a small water change at the end of each day where clean up the bottom of the tank and pull out a little of the water, send it back to my 55 gallon, and then use water coming from the filter on my 55 gallon to replace into the nursery tank. Its bare bottom, I do have a little java moss in there for security and hiding and all those nice things that babies like that came from my big tank and a couple snails just for cleanup assistance.

My question: How do I know my fry are eating? I'm pretty limited when it comes to magnification to get super close looks at them I've been using my cell with zoom with the best clarity to try to look at their bellies. I'm just not sure if they're eating yet. I am using Hikari First Bites. I take a little water from the tank into a tiny cup thing and dip a dry chopstick into the powder then stir it into the water. I let that sit for a couple of minutes then try to distribute the food out across the entirety of the small area of the 2.5 gallon.

I'm just not sure if they're eating. They're not overtly active currently. I guessed its because they're like 3 days old now. I'm generally just worried about keeping them alive. I am doing about 4 small feedings per day and my end of day is when I do the cleaning to clean up as much of the bottom as I can and water change. I've read a lot on the subject my concern now is just them eating.

I'd like to have them live and use them in a 29 gallon tank that I'm setting up for shrimp just because I think a shrimp colony would be cool to watch.

If anyone with experience has any information on what I should look for or how long it may take before I can observe what its like "typical" behavior - that would be awesome.
what I know from raising egg fry in general is this is fine and your plan is fine. they are on egg sac for a few days of swimming around. By the math, today is day 3, somewhere between now and day 4 they will eat. they really won't eat if they have the egg sac still.

With my angels I'm never sure they are eating either for the first couple weeks until they get bigger and it becomes obvious they are, but they weren't really all dying either and seemed to be growing so I assumed they must be eating and not starving.

Most of this is feeding advice for growth, here is the feeding tip and how to know for sure they eat:
What I know is if you feed baby brine shrimp, you will be able to tell who's eating and who isn't because as they eat, the baby brine shrimp will make their bellies an orange color.

From my experience with fry they are the most fragile in the first month and becomes less so as the weeks pass, and it's imperative to feed in a manner that promotes fast growth to get them beyond that tiny and weak point so they can eat bigger things and thrive.

you can feed 2x a day, they will burn a lot of that between feedings swimming around and if you feed big, a lot of that will go to waste, this is slow growth.

you can feed 4x a day, in smaller feedings, this is every 6 hours roughly, this gives them something through the day, there's less waste and they can put on mass which will be put to growth. this is a good rate most folks use and doesn't interfere with sleep too much.

you can feed 6x-8x a day also, every 3-4 hours, a little bit each time, so theres always something fresh to eat in the tank to put on calories and weight.
Technically you could feed every 2 hours, that's about as long as a fish needs to process what they eat through their system and take what they can from it and get rid of what they can't use as waste.

I was looking into a trustworthy autofeeder to help with the feedings so I could maximize early growth without having to be there for feedings, but I didn't settle on anything I felt I could trust to not overfeed and dump in a ton at once, or miss feedings completely.
So I aimed for around 6 feedings a day with that 4 feeding mandatory minimum and just add in more little feedings here or there after 2 hours pass after a feeding when I can.

the more often you feed them, not quantity of food but frequency of the feedings, the faster growth you'll get because they will put on mass with whatever extra they get that they can use that doesn't become waste, i've never gotten fat fry or juveniles doing this.

You'll be cleaning every day anyways, I did the same, so nothing is sitting there breaking down and polluting the water for long.

Best of luck.!
 

DuchessNeeka

Since its Friday, I was able to do a better clean on the lil 2.5g. There's 12 fry instead of my initial estimated count of 7 - a couple groups of them were hanging out in the black part in the corners and I couldn't see them hah. They've been a little more active this evening as well a couple seem to enjoy the filter area - specifically the pantyhose meshy barrier I rigged to protect them.

Here's a couple images of ones that like to hang out more toward the front but I can't tell if the belly is yolk sac still (third image is 1x zoom and the others are more like 3 or 4x). The images were taken a few minutes ago so they're very new. And a video of a couple of them that looks kinda like they're eating, I guess lol, that I uploaded to YT.

Getting them to eat is my next goal - I was the same way when I got my snake. He was very young and I had read that some just starve themselves to death from the stress of shipping, etc. Thankfully, my snake is always hungry. He almost never refuses a meal.

 

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Flyfisha

I am of the opinion that corydoras fry do not need a sterile tank to survive? Unlike some species that are more susceptible to fungus etc. While cleaning often is never a bad thing especially in a 2-5 gallon I would be adding old ornaments,old moss ,old leaf litter ,plant material etc and anything that has micro organisms in/ on it.
Baby brine will swim towards a light source. To have any chance of the corydoras fry eating them before they die place a light under the tank in order to attract the bb. Micro worms will sink down towards the fry and stay alive in fresh water.

Another point is the young that turned up in your tank had no special food but they had a nice dirty tank to find food. Even a dirty sponge filter is an excellent food source for these fry.

I am a fan of bare bottom tanks but in this case I don’t think it’s ideal for fry in a 2-5 gallon ?
 

SparkyJones

I'm of an opposing opinion. I don't like a dirty tank because they shouldn't be eating poop, and that's basically all fry do, eat grow and poop. I don't think it needs to be sterile, but no good comes from poop laying around either and the more clutter, the harder it is to get it out of there. I have no issue with ground up algae wafer, or ground sinking pellets being put in there for them to forage around for that will sit on the bottom, algae not being ideal but works if a fish gets hungry and are lazy.. But I think it's real important that the fish poop stays out of reach and with cories, I don't like gravel, which will get it out of reach but in general hurts them trying to sift through and sand is too hard to clean effectively regularly and generally keeps it on top and in reach.

I don't know enough about leaf to feel comfortable recommending that As a substrate, I know there's some toxic stuff, and in a small space that can be a problem where in a river it's so diluted it wouldn't matter. Something I can't advise on but to say don't just blindly get some leaves and toss them in there.

I dunno. I like the bare bottom because there's nothing to hurt them and you can get the poop on out of there easily.
I also like the addition of the plant in there. gives them hiding spots and something to forage through, bithout being really hard to work around to clean.
2.5 gallon is fine for a couple weeks, it makes it easy for them to find the food without spending a lot of energy, however that won't last long before they outgrow that size and need more room. Smallest I go is a 10g for fry but my spawns with angels have been hundreds of fry. even then it's a month before you need a 20g and then another month to a 40g. A dozen fish isn't much though, pretty sure you can tell when it will be time to size up the tank.

I have friend that had cories in a lightly planted community 55g tank and did nothing special just left them there and a couple survived and grew out to adults from each spawn. They are pretty hardy.

Not really sure of the best way to go here. I'd think though as long as they have food options each day they gonna be fine. Whether they forage for little bits left overs from feedings or artemia or bbs or pick up some algae or biofilm, they seem pretty flexible as long as there's something around to eat.
 

DoubleDutch

Coryfry does better (by far) on a thin layer of sand than on a bare bottom
 

SparkyJones

Coryfry does better (by far) on a thin layer of sand than on a bare bottom
I was thinking about this but what do you do? Put a bit down, suck it up vacuuming, and put down some more? Really careful with vacumming?
 

DuchessNeeka

I used a lot of different information from other locations, local breeders and a thread in this forum (Raising cory fry | Corydoras Forum | 204003)

I do have some catappa leaves coming and I added a small piece of driftwood along with the moss (stuff I can easily remove out or move around to clean the bottom then add back).

All of the guides that I read stressed cleanliness of the bottom which is what I try to achieve. My only substrate is black sand and I really don't feel comfortable using it with how small and difficult they already are to see. It would bring me great anxiety. I'm a hover mom with new babies of any kind.

I'll be giving them substrate as they get bigger. I know my big Corydoras enjoy the sand a lot.
I think someone somewhere else told me they add some substrate once they're in a grow out tank.

I am looking into other food sources as well. This will be my only little hatching expedition. I wanted to see if I could do it and, if so, it got me the Corydoras I wanted for the new tank in the works which I'm really only getting away with being able to do because the tanks, and my other animals, ease my anxiety and other symptoms of other things. So I'm trying to find a breeder or fish store that can sell to me small batches of like bbs or microworms.
 

MacZ

I was thinking about this but what do you do? Put a bit down, suck it up vacuuming, and put down some more? Really careful with vacumming?
Thoroughly established tank with leaf litter and mulm as I know DD.

What you describe above is, frankly, overdoing it with the cleaning, although you have no other choice with your way of setting up a grow-out. So basically you are making it harder for yourself than you have to.

An established leaf litter bed can easily break down the feces the fry produce without deteriorating water quality. You only have to stick to a diciplined waterchange regimen. That's all.
 

DoubleDutch

Though vacuuming very carefully is an option. Even in a bare bottomtank there will grow fungus / bacteria on the "dirt" on the bottom (it won't stay sterile).
Somehow the thin layer of sand gives the best result I suspect it has to do with a kind of cleaning of the barbels when shifting through and over the sand.

Leaflitter will establish infuseria growth what will be great for the tiny ones.
My best results I had with microworms after that stage. As mentioned : they stay alive for some time so there is a constant supply of living food without the risk of fungussing and bacterial growth.
 

DuchessNeeka

So its been about a month since I posted regarding my Corydoras fry. I actually ended up with 15 after finding a couple more in my 55g. They stayed in the 3.5 gallon until yesterday where I moved them to a 29g partially filled with a seeded sponge filter.

I took advice from some and read many a guide and did what was accessible for me. Specifically regarding the sand, it isn't fully bare bottom. I pulled some sand from the big tank. The rest will come as my decorations get in

They seem to be enjoying the space, they've been digging around and travelling all over like their parents do in my big tank. I suppose I can take that as a good sign.

Its super basic right now. I have plans for the decor of the tank, I just have to get the items in for it. Right now the tank is just for them to get a little bigger then I'll be selling, trading, or giving away some of them to make sure I don't overstock. I'd like to put some danios or something in the tank too. Plus I want to separate the males and females in the big tank so no more babies.

It has been fun so far watching them grow but without a reliable place for them to go, I don't want tons of Corydoras.

Please ignore the thermometer in front. I have a sinus and respiratory infection and in my yucky feelings, I dropped the digital one in the water which of course broke it. I have more coming. Since it was one I stole from my snake tank for the 55g then took it again to keep temps in check with fry nursery - it'll be chucked out once those come in.
 

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DoubleDutch

So its been about a month since I posted regarding my Corydoras fry. I actually ended up with 15 after finding a couple more in my 55g. They stayed in the 3.5 gallon until yesterday where I moved them to a 29g partially filled with a seeded sponge filter.

I took advice from some and read many a guide and did what was accessible for me. Specifically regarding the sand, it isn't fully bare bottom. I pulled some sand from the big tank. The rest will come as my decorations get in

They seem to be enjoying the space, they've been digging around and travelling all over like their parents do in my big tank. I suppose I can take that as a good sign.

Its super basic right now. I have plans for the decor of the tank, I just have to get the items in for it. Right now the tank is just for them to get a little bigger then I'll be selling, trading, or giving away some of them to make sure I don't overstock. I'd like to put some danios or something in the tank too. Plus I want to separate the males and females in the big tank so no more babies.

It has been fun so far watching them grow but without a reliable place for them to go, I don't want tons of Corydoras.

Please ignore the thermometer in front. I have a sinus and respiratory infection and in my yucky feelings, I dropped the digital one in the water which of course broke it. I have more coming. Since it was one I stole from my snake tank for the 55g then took it again to keep temps in check with fry nursery - it'll be chucked out once those come in.
Well done !
 

Debbie1986

nice set up for fry ana that baby is a cutie!
 

SparkyJones

they are doing really well! niiiiice!
 

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