10 Gallon Tank Pygmy Cory’s spawned, not sure what to do.

Hi everyone! I returned home from a day trip, and I turned on the lights for my Pygmy Cory (C. pygmaeus) breeding tank, and the walls were COVERED in eggs. I counted over 70, and I want to make sure that as many will make it as possible. I’ve tried breeding these guys before, but I’ve only had small spawns with fry that didn’t make it. For anyone wondering, I have a specimen container with an air stone that I put some eggs in, and I don’t have any live foods like micro worms or BBS, but I have Hikari First Bites. Let me know if there is anything I can do, especially if there is a better incubation/fry raising setup I can put together.

 

Hi everyone! I returned home from a day trip, and I turned on the lights for my Pygmy Cory (C. pygmaeus) breeding tank, and the walls were COVERED in eggs. I counted over 70, and I want to make sure that as many will make it as possible. I’ve tried breeding these guys before, but I’ve only had small spawns with fry that didn’t make it. For anyone wondering, I have a specimen container with an air stone that I put some eggs in, and I don’t have any live foods like micro worms or BBS, but I have Hikari First Bites. Let me know if there is anything I can do, especially if there is a better incubation/fry raising setup I can put together.

Don’t suppose you can get any vinegar eels, or microworms? You could try hatching baby brine shrimp - not hard to do and they’d be so much better quality food than First Bites for new fry.

Do you happen to have any of the little ramshorn snails? A local cory breeder here uses them to take care of eggs with fungus instead of using meth blue or trying to hand pick bad eggs out. They will not touch healthy eggs but they eat fungus and dead eggs.

The Pygmy cories don’t usually eat their fry so it’s ok to leave the eggs in situ.

 

I’ve been meaning to get some vinegar eels, but unfortunately there aren’t any shops near me that carry them, and I haven’t been able to find them online. I’ll see if I can find some BBS eggs, as with those I should be able to order them online.
Using snails to remove any fungus/dead eggs sounds like a really good idea! I don’t have any ramshorns, but do you think cherry shrimp would work?
Also, I do plan to keep about half of the eggs in the breeding tank with the adults, but I do want to artificially raise some as I’ve heard varying results from the prior method.

 

You could use a razor blade to remove some eggs and leave some and do some research. See what the hatch rates are vs each.
You don’t need to feed until the yolk sacks are absorbed / eaten , maybe 3 or 4 days after hatching depending. You have time to hatch bbs or source them. You can also try feeding boiled egg yolk, in very small amounts, be careful of the water quality though.

I’ve used hikari first bites 4x a day then 3, then live foods with great success for fish ( not catfish though ) so I see no reason why you couldn’t use that.

remember that fish release growth hormones and water changes are needed to dilute them.
remember that fish release growth hormones and water changes are needed to dilute them.

edit — do you have catappa leaves ? If so soak half of one in tepid ( not boiling ) water and put it in with the eggs you take out of the tank. That’s anti fungal properties( if you boil you’ll release a lot into the boiling water and lose a lot of the benefits ) , you can use meth blue but I personally don’t like that if you can use botanical methods .

 

You could use a razor blade to remove some eggs and leave some and do some research. See what the hatch rates are vs each.
You don’t need to feed until the yolk sacks are absorbed / eaten , maybe 3 or 4 days after hatching depending. You have time to hatch bbs or source them. You can also try feeding boiled egg yolk, in very small amounts, be careful of the water quality though.

I’ve used hikari first bites 4x a day then 3, then live foods with great success for fish ( not catfish though ) so I see no reason why you couldn’t use that.

remember that fish release growth hormones and water changes are needed to dilute them.

I’ve removed about half of the eggs so far, and I’ll see if I can hatch some BBS. Also, didn’t know about the growth hormones affecting water quality, so thanks for letting me know!

 

I’ve removed about half of the eggs so far, and I’ll see if I can hatch some BBS. Also, didn’t know about the growth hormones affecting water quality, so thanks for letting me know!

I roll my finger over the eggs to move them, the sticky part of the egg will attach itself to your finger, to get the eggs off, roll them on another surface, to get rid of bad eggs I use a pipet to suck them up, for the first little while I add moss as food for the babies, all the little micro bits of food and matter in the moss make good food for the babies plus adding cover for them, you can sort of tell when an egg is dead when the center turns white, I do trying to recommend getting a ramshorn snail as fungus control.

 

The fry all release growth hormones , the biggest fish will do the best and the smaller fish will suffer. To get the biggest amount of fry that grow relatively stable you’ll need regular water changes , they don’t need to be large but they do need to be regular to dilute the hormones

good luck. Please keep us updated on how the fry grow !

 

Blacksheep1 is correct; however, with growth hormones, it's not the actual "growth hormone" that stunts - instead, it's the GIH, or growth inhibiting hormone. Fish use this to suppress another fish's growth and can even suppress theirs if conditions are crowded enough.

Wonder why people talk about "stunted growth" in goldfish? They say it's water quality, bad food, overstocking, stress, and that stunted growth will kill fish...non of this is true. Carp (goldfish included) can live through an apocalypse. Not only that but they produce GIH in the wild too - even in giant lakes. One thing to note is that all of the oldest-living goldfish were stunted.

This may not sound relevant to the conversation, but it is. Although not much research is done for catfish relating to GIH and life expectancy, small animals often live longer than their counterparts. Think chihuahuas living 20 yrs while great danes only live around 6-8, or miniature horses living 40 yrs but the biggest horse breeds living only 20 at most. It's a similar situation with fish too.

For most fish, stunting is in fact good for the fish - a smaller size means more food and space is available, allowing fish to grow up healthier and often live longer. Unfortunately, I know all of this with many years of experience with goldfish, but I'm not so sure if this is the same with corydoras

What I'm saying is, stunting can be good, but an overstocked tank full of sick, stressed fish isn't. So use all of this as you please. Do your frequent WCs if you choose, manually remove dead eggs, use methylene blue or snails, or don't do any of it. It's all up to you on what you want to do. The most important thing with fry is having plentiful food and low ammonia if you have high pH (low pH produces ammonium only which is generally considered non-toxic.) Nitrite isn't toxic for the most part, but it probably is for fry. High nitrate isn't usually either, but may be for fry. Fry are a lot more sensitive than adult fish, so I suggest doing relatively frequent water changes; maybe every few days or so. Check water parameters at least weekly and do water changes if anything looks off. I've done this for 12 years. If it works, it works!

As for food, this also depends on you. Many use hikari first bites with great results but some say the ingredients are bad (which is somewhat true - despite the high price tag, hikari's not too good when it comes to fish food ingredients.) Various worms like micro and vinegar eels are great but they're hard to find, can be expensive, and many times the colonies fail. Baby brine shrimp are a great source of protein and are fairly easy to find and hatch yourself. It may start to get expensive with hatching and feeding brine every 24 hrs but they'll grow up healthy. Another are daphnia and moina - "water fleas" - basically the same thing. They're very easy to raise on plain algae and are healthier than most live foods (bloodworms can cause bloating if fed too frequently, but daphnia and moina are a great way to treat this issue.)

So overall, one way to raise fry may not be the way you'd want to go, depending on your water. Catappa (indian almond) leaves are great and all but don't use them if you have low pH unless it's what you want. Tannins, CO2 from injection and high surface agitation, and high nitrogen caused by detritus can cause the pH to drop. Carbon will cause the pH to rise dangerously. I haven't used carbon in over 8 yrs. It's completely useless. My water from the tap has a pH of 6.8 - in a normal tank without high flow the pH buffers to 6.6, but in a tank with high flow the pH can be as low as 6.4 - too low for most fish besides anabantoids (labyrinth fish), and probably for cories too.

Anyway, sorry for the long reply, but I'm trying to cover everything in hopes that this'll help. Good luck

 

JustAFishServant , I know , but the op is a new member and I was trying to give context without over whelming info. You’re correct , but if they don’t know that to start with then a deep dive on information can be somewhat too much .. maybe . I love that you are factually correct though

Half a catappa leaf won’t change the pH of the entire tank in a breeder box , but it will provide a concentrated hit of beneficial humic substances for the fry, that will provide anti microbial properties , with the potential growth of free micro food. As mentioned above , moss will be massively beneficial , it holds a lot of micro fauna that the fry will happily feed off.

Good luck with the fry !! I hope they do well for you

 

JustAFishServant , I know , but the op is a new member and I was trying to give context without over whelming info. You’re correct , but if they don’t know that to start with then a deep dive on information can be somewhat too much .. maybe . I love that you are factually correct though

Half a catappa leaf won’t change the pH of the entire tank in a breeder box , but it will provide a concentrated hit of beneficial humic substances for the fry, that will provide anti microbial properties , with the potential growth of free micro food. As mentioned above , moss will be massively beneficial , it holds a lot of micro fauna that the fry will happily feed off.

Good luck with the fry !! I hope they do well for you

Oh sorry...yep I'm guilty of "overwhelming info"

When you say "moss" what do you mean? Dry (like sphagnum for plants), live (java moss or moss-like ferns like Sußwassertang), wild picked ones (which could hold onto toxic substances within their roots) or something else? I assume you mean some sort of live moss containing microorganisms like small detritus worms and infusoria...

On a similar note, fish make quick work of fungus knat or carpet beetle larvae

 

Oh sorry...yep I'm guilty of "overwhelming info"

When you say "moss" what do you mean? Dry (like sphagnum for plants), live (java moss or moss-like ferns like Sußwassertang), wild picked ones (which could hold onto toxic substances within their roots) or something else? I assume you mean some sort of live moss containing microorganisms like small detritus worms and infusoria...

On a similar note, fish make quick work of fungus knat or carpet beetle larvae

Is that to me? I use both Marimo moss and Christmas moss.

 

I meant just regular tank mosses like Java or Christmas

 

If you're trying to raise the most that you can, a daily 25% water change and remove waste and feed something every 4-6 hours. They won't always eat but most tanks (unless they are old and well planted) lack an environment where fry can constantly forage when they are hungry, so frequent small feedings is the way to go to not suffer from fry starvation losses.

Fry are real sensitive for the first few weeks to feeding routine, they don't have fat stores or body mass built up yet, it's easy to starve them if they can't find food for energy/activity needs and gain in body mass so they can grow and get a store that will make them hardier and less likely to die.

They will need to eat about 24 hours after the egg sack is absorbed, established tanks can get them over the first feeding or so but if you got dozens to 100 they will exhaust what the tank can sustain in a day or two usually unless its a jungle with detritus worms and all the little critters in there.
One or two feedings a day isn't gonna work until they are older and in the juvenile size, you really want them gaining body mass to grow and the energy they need to do their thing, not overfeeding but giving lots of opportunities to eat through each day and fresh food going in that they can forage for between feedings for the slackers.

For me with fry the hardest was figuring out the feeding. You are gonna give them lots of opportunities to eat but not so much they are bulging or full, they are going to poop a lot also because of this method and that's the main reason for the daily water change, to remove waste. The growth hormone thing just doesn't become a concern with the water changes like that.

If they won't take first bites you may have to go with egg yolk for a week to get some mass and size on them for them to be able to eat bigger bits. It's just hard boil an egg and remove the center, then mix a bit with tank water into a yellow slurry and dump in in. If you have to go that route you might want to do a bigger water change, theres a lot more food waste by feeding yolks. But that can get you over the hump with small fry and tiny live foods aren't an option for you.

Good luck!

 

Blacksheep1 is correct; however, with growth hormones, it's not the actual "growth hormone" that stunts - instead, it's the GIH, or growth inhibiting hormone. Fish use this to suppress another fish's growth and can even suppress theirs if conditions are crowded enough.

Wonder why people talk about "stunted growth" in goldfish? They say it's water quality, bad food, overstocking, stress, and that stunted growth will kill fish...non of this is true. Carp (goldfish included) can live through an apocalypse. Not only that but they produce GIH in the wild too - even in giant lakes. One thing to note is that all of the oldest-living goldfish were stunted.

This may not sound relevant to the conversation, but it is. Although not much research is done for catfish relating to GIH and life expectancy, small animals often live longer than their counterparts. Think chihuahuas living 20 yrs while great danes only live around 6-8, or miniature horses living 40 yrs but the biggest horse breeds living only 20 at most. It's a similar situation with fish too.

For most fish, stunting is in fact good for the fish - a smaller size means more food and space is available, allowing fish to grow up healthier and often live longer. Unfortunately, I know all of this with many years of experience with goldfish, but I'm not so sure if this is the same with corydoras

What I'm saying is, stunting can be good, but an overstocked tank full of sick, stressed fish isn't. So use all of this as you please. Do your frequent WCs if you choose, manually remove dead eggs, use methylene blue or snails, or don't do any of it. It's all up to you on what you want to do. The most important thing with fry is having plentiful food and low ammonia if you have high pH (low pH produces ammonium only which is generally considered non-toxic.) Nitrite isn't toxic for the most part, but it probably is for fry. High nitrate isn't usually either, but may be for fry. Fry are a lot more sensitive than adult fish, so I suggest doing relatively frequent water changes; maybe every few days or so. Check water parameters at least weekly and do water changes if anything looks off. I've done this for 12 years. If it works, it works!

As for food, this also depends on you. Many use hikari first bites with great results but some say the ingredients are bad (which is somewhat true - despite the high price tag, hikari's not too good when it comes to fish food ingredients.) Various worms like micro and vinegar eels are great but they're hard to find, can be expensive, and many times the colonies fail. Baby brine shrimp are a great source of protein and are fairly easy to find and hatch yourself. It may start to get expensive with hatching and feeding brine every 24 hrs but they'll grow up healthy. Another are daphnia and moina - "water fleas" - basically the same thing. They're very easy to raise on plain algae and are healthier than most live foods (bloodworms can cause bloating if fed too frequently, but daphnia and moina are a great way to treat this issue.)

So overall, one way to raise fry may not be the way you'd want to go, depending on your water. Catappa (indian almond) leaves are great and all but don't use them if you have low pH unless it's what you want. Tannins, CO2 from injection and high surface agitation, and high nitrogen caused by detritus can cause the pH to drop. Carbon will cause the pH to rise dangerously. I haven't used carbon in over 8 yrs. It's completely useless. My water from the tap has a pH of 6.8 - in a normal tank without high flow the pH buffers to 6.6, but in a tank with high flow the pH can be as low as 6.4 - too low for most fish besides anabantoids (labyrinth fish), and probably for cories too.

Anyway, sorry for the long reply, but I'm trying to cover everything in hopes that this'll help. Good luck

No worries about the long reply! I think that for now, I’m going to do a water change right before each time I feed, both to remove any uneaten food, waste, or GIHs. This seems very interesting to me though, so I may experiment with it in the future. Thanks for the info!

JustAFishServant , I know , but the op is a new member and I was trying to give context without over whelming info. You’re correct , but if they don’t know that to start with then a deep dive on information can be somewhat too much .. maybe . I love that you are factually correct though

Half a catappa leaf won’t change the pH of the entire tank in a breeder box , but it will provide a concentrated hit of beneficial humic substances for the fry, that will provide anti microbial properties , with the potential growth of free micro food. As mentioned above , moss will be massively beneficial , it holds a lot of micro fauna that the fry will happily feed off.

Good luck with the fry !! I hope they do well for you

A few days ago, I bought some Java moss from a LFS, and I got a plant shipment including even more of it today. Do you know if this wound work, or if I would need to let microorganisms “colonize” in it?