Cory breeding question     /RMF   12/19/14
Hi WWM! My name is Stephanie.
<Hello Steph>
I came across your site while I was looking for some Cory breeding information. I've had an assortment of cories in my tank for almost 2 years now, and have a few questions1) I found around 80 Cory eggs over the course of 2 days. I moved them into a floating breeder with some java moss under the filter outflow. Two days later, four hatched. I moved the breeder into
calmer waters. Over the next day, the eggs began to disappear, but still only four fry. Today (day four), there are only 2 eggs left and 10 fry total. Is it possible that some of these eggs just decompose?
<Oh, yes>
I'm certain that they were viable, removed any that fungused (only about 10), and nothing has died or escaped. I'm just curious about the hatch rate I guess.
<These percentages improve w/ maturity of the breeders, conditioning (mainly feeding) and care in terms of optimized water quality>
I had hoped for more! Although, this is my first time with any species of fry!2) It seems that a few weeks will give the cories a good amount of time to grow, but I was wondering how soon you can tell what species they are?
<Mmm; depends on the mix of species... oh, I see you state below... but a month or two>
I have 5 different species in my tank. I assume it's the bronze, because I have 9 good sized ones, although they have just reached their maturity and this would be their first spawn, so I was surprised at so many fertilized eggs.3) What is the chance that a 1m to 1f ratio would produce fertile eggs?
<Okay; better than half, even three quarters>
I have 2 rabauti that I absolutely love and want more of, but cannot find them anywhere around here. I assume a separate breeding tank would be my best bet.4) I also noticed that one of the smaller bronze cories that I've had for a while has flukes on his fins.
<Really?>
The others seem fine, aside from an occasional flash (i.e.: no visible symptoms besides behavior). I also have swordtails, silver dollars, and tetras which show no behavioral or visible symptoms. I assume I should treat the entire tank because I know I've seen them on other fish that I have since lost. Is medicating a tank harmful to the fry?
<Depending on what is used, yes, can be>
I assume they are much more sensitive to it, but wasn't sure. To add on to this - I do have another tank that I can use, but I am waiting for 2 new sponge filters to get here so I have no filter or seeded media available should I quarantine the affected fish. Should I still quarantine and perform numerous water changes, or should I move the fry to the empty tank since I'm doing WCs for them anyway and then set up the brand new filter when I receive it?
<Best to go with this last plan; but do provide "squeezings" from the old/established filter to the new tank... and get all water from the old tank for the new>
Too much going on at one time. Anyway, I appreciate any response as my web searching has not clarified these last few issues for me. Thanks!
<Welcome. Bob Fenner>
Cory breeding question        /Neale        12/20/14
Hi WWM! My name is Stephanie. I came across your site while I was looking for some Cory breeding information. I've had an assortment of cories in my tank for almost 2 years now, and have a few questions
1) I found around 80 Cory eggs over the course of 2 days. I moved them into a floating breeder with some java moss under the filter outflow. Two days later, four hatched. I moved the breeder into calmer waters. Over the next day, the eggs began to disappear, but still only four fry. Today (day four), there are only 2 eggs left and 10 fry total. Is it possible that some of these eggs just decompose?
<Yes. Non-fertilised eggs will surely decompose, and in community tanks, it's often the case other fish and even snails will eat some of them. If you have a mix of species, eggs fertilised by males of a different species may have a lower chance of developing. So given the situation, getting 10 fry isn't bad at all.>
I'm certain that they were viable, removed any that fungused (only about 10), and nothing has died or escaped. I'm just curious about the hatch rate I guess. I had hoped for more! Although, this is my first time with any species of fry!
<Corydoras are an excellent species for the beginner. By the standards of other egg-scatterers, they're big eggs, and the fry are comparatively easy to rear. Not quite as easy as livebearer fry, or looked after by the parents as well as some cichlids (such as Kribs) that do the work for you -- but still pretty easy.>
2) It seems that a few weeks will give the cories a good amount of time to grow, but I was wondering how soon you can tell what species they are? I have 5 different species in my tank. I assume it's the bronze, because I have 9 good sized ones, although they have just reached their maturity and this would be their first spawn, so I was surprised at so many fertilized
eggs.
3) What is the chance that a 1m to 1f ratio would produce fertile eggs?
<See above.>
I have 2 rabauti that I absolutely love and want more of, but cannot find them anywhere around here. I assume a separate breeding tank would be my best bet.
<Yes.>
4) I also noticed that one of the smaller bronze cories that I've had for a while has flukes on his fins. The others seem fine, aside from an occasional flash (i.e.: no visible symptoms besides behavior). I also have swordtails, silver dollars, and tetras which show no behavioral or visible symptoms. I assume I should treat the entire tank because I know I've seen them on other fish that I have since lost. Is medicating a tank harmful to the fry?
<Can be, yes. Best to remove fry. Methylene blue is safe with fry, and antibiotics too, and probably salt/heat treatments, but otherwise avoid medicating tanks with fry.>
I assume they are much more sensitive to it, but wasn't sure. To add on to this - I do have another tank that I can use, but I am waiting for 2 new sponge filters to get here so I have no filter or seeded media available should I quarantine the affected fish. Should I still quarantine and perform numerous water changes, or should I move the fry to the empty tank since I'm doing WCs for them anyway and then set up the brand new filter when I receive it? Too much going on at one time.
<Indeed. Rearing Corydoras fry in a breeder trap is doable for a few weeks.
Keep on top of feeding (6-8 small meals/day) and water quality (minimise nitrate; zero ammonia and nitrite). Set up the rearing tank. As/when it's ready, move the fry across with as much of the aquarium water as possible to minimise shock.>
Anyway, I appreciate any response as my web searching has not clarified these last few issues for me. Thanks!
<Do read:
http://www.wetwebmedia.com/fwsubwebindex/armcatreprofaqs.htm
http://www.wetwebmedia.com/fwsubwebindex/coryreproart.htm
Much else written in books, online about breeding this genus. Good luck,
Neale.>
Re: Cory breeding question      12/28/14
Thanks Neale!
I am happy to report that I still have six of the original fry (9 days old) and they're getting pretty big!
<Great.>
I also had another batch of eggs so I have an additional 48 new two day old fry! I was wondering when I can put the two together without facing predation or food competition issues.
<Not until the youngest ones are at least a couple months old, maybe three months. It does depend on the size of the tank though. But otherwise, if you try to put enough food in there that the smallest fry get enough as well as the biggest fry, you end up with high nitrate levels. That in turn causes fry to die. It's just a lot easier to segregate fry on the basis of
size (age doesn't really matter) maybe into two, three or even four batches. A tank divider can be used if you all want them in one tank, and that can make it easier for different size fry to get access to food without you adding so much food nitrate goes up.>
I have a spare 20 gallon and have had my new filter seeding in another tank for a week. How much longer should I wait for bacteria to colonize?
<Hard to say, but usually if you add across mature filter media, new filters mature instantly (or a few days if the proportion of mature media is less than 50% the capacity of that new filter). Don't forget to "feed" filters if there aren't fish in the tank, otherwise any bacteria will die off.>
I don't want to endanger the fry by moving them too soon but with their size and all the water changes I assume the bioload will be quite small, so I thought maybe a week could be sufficient but I'm not sure.
<Likely so. Worth trying, especially if you have many fry, and can add a dozen today, a dozen a couple days from now, and so on.>
I would like to move them sooner rather than later because my silver dollars are knocking the breeder boxes around.
Thanks!
<Cheers, Neale.>

Albino Corydoras bubble nesting?    1/14/13 Hi there. I have two albino Cory cats in a 10 gallon tank with my Betta boy. The larger of the Corydoras has always been a very busy, robust fish. For the last month or so, he <Mmm, she>  sometimes sits at the top of the tank, seemingly making a bubble nest. <Ah, no... Corydoras as substrate spawners... but do facultative (non-obligative) aerial respiration... as many Amazonian fishes are capable of... the bubbles are likely from polar molecules in the water (foods, wastes... lack of complete filtration, insufficient water changes)... coalescing/keeping exhausted air bubbles encapsulated... from the cats, Betta> I know there are some catfish that do make bubble nests, and that Corydoras are not among them... <Correct> so, any thoughts on the behavior? <Breathing from the surface, exhaling underwater> The tank is about a year old, cycled, stable. It has several live plants, and no surface "oil" that would prevent oxygen transfer. <Ahh! Good point> I wonder if the fish is actually a different species (though it looks like a Cory to me) or if the little fella thinks he's a Betta... just kidding. I would appreciate your insight. <As stated. Quite common. Bob Fenner>

Peppered Cory stopped in the middle of spawning - 8/17/12
Hello,
My name is Constantin and I have a 20 gallon planted tank (the current configuration of the tank and stock were constant for 8 months now) with 9 tiger barbs, 4 peppered Corys (3 females and one male apparently) and some MT snails in it. Yesterday I've noticed that one of the Corys had eggs in between her fins and decided to deny the tigers of a delicious meal and move the Corys.
I moved them in a 5 gallon (half of the water coming from the main tank, half from the tap after using conditioner). Immediately (10 min) after moving them, one of the Corys laid 3 eggs on the tank's glass. The male was very active during the whole time (the T position and everything). The weird thing (at least for me) is that they suddenly stopped. Although the females seemed interested and continued to "court" the male, he just didn't care anymore and kept hiding in a small cave.
This morning I did a pwc (30%), lowered the temperature with a couple of degrees and fed them  worms (live Grindal and frozen bloodworms) - the same worms I gave them for the last months. Still, nothing. They are doing fine in the new tank but do not show any interest in spawning.
So, my question is: should I let them in this tank a little more (for how long?) and see what happens or, just give up and put them bank in the main tank?
Thank you,
Constantin
<For whatever reason, Corydoras spawn better in groups of 2 males and 1 female. In any case, if they have stopped breeding, try "conditioning" them some more in the main aquarium (lots of live or frozen foods!) and see what happens tomorrow or the next day. Corydoras like to spawn in the morning, and early morning sunshine can be a good spawning trigger. You can let them spawn in the main tank and remove the eggs promptly to the breeding tank if you don't want to move the adults. In the meantime, read here:
http://www.wetwebmedia.com/fwsubwebindex/coryreproart.htm
Cheers, Neale.>
Re: Peppered Cory stopped in the middle of spawning - 8/17/12
I'll follow your advice. Thank you very much.
Constantin
<Most welcome, Neale.>

 

TWO BATCHES OF FRY    6/19/12
Hi there,
<Gillian,>
I have 16 bronze Cory fry in a tank - they hatched about a month ago.
<Well done!>
About 1/3 of them are relatively big - look like small versions of their parents and the rest are still relatively small.
<A common problem. With all fish fry, you will find that if you don't separate off the bigger fry, they'll steal food from the smaller ones, so you end up with a few big fry and lots of dead fry. That's evolution in action -- survival of the fittest, so out of the hundreds of eggs spawned, only the few strongest reach maturity.>
I decided that it would be unwise for me to save any more eggs from my main tank as space would become a problem but when I saw some more eggs about a week ago, I put them in the "fry" tank and they hatched on the weekend.  I did notice a couple of them swimming around but now I don't see them anymore - is it very possible that the older fry have eaten them or is it more likely that they may have found a safe spot in my tank and will stay out of sight until they are larger?
<Both are possible and hard to say from where I'm standing.>
I thought at the time that I put the eggs in their tank that my month old fry may still be too small to go after any hatchlings and they are regularly fed so much so that they wait for their food rather than go sucking around the tank.  Was I incorrect and should I give up staring at my tank in the hopes that they are still alive ?
<I wouldn't bet the house on their survival, no.>
Thanking you for your assistance.
Regards, Gillian
<Most welcome. Do read: http://www.wetwebmedia.com/fwsubwebindex/coryreproart.htm
Cheers, Neale.>
Re: TWO BATCHES OF FRY   6/20/12
Thanks so much for your prompt reply.  I must admit - the news you provided was not what I was hoping for but certainly what I was expecting.
<Indeed.>
Fortunately the smaller ones of the first batch are definitely being allowed to eat by the larger ones so I am hoping they do make it to adulthood - and I feed them half a bottom feeding tablet every morning and evening so I think there is plenty - if not too much - food in the tank.
<Difficult to assure. But see what happens. Obviously if you offer so much food the big ones are satiated, then the smaller ones will be able to eat… but the risk is that all that food raises water quality problems. Nitrate levels in particular have a negative impact on the growth of baby fish. Often, getting fish to spawn is easy, and rearing a half dozen fry is easy, but rearing dozens or hundreds of them a major challenge, even with "easy to breed" species like Corydoras or Danios.>
They are also in a 2ft tank so they are not having to fight for a small space.  I did have 21 to begin with - 3 died and 2 have "disappeared" (I know they are dead I just don't know where or how they died).
Thanks again for your help, I appreciate it!
<Most welcome, Neale.>

 

Corydoras eggs    5/20/12
I hope you can give me some advice.
<Will try.>
I have a 10 gallon tank with 6 Corydoras and 10 zebra danios. (Yes the tank is a bit small but I'm keeping it clean and they have all been healthy; we plan to buy a bigger tank in a few months.)
<Cool.>
Today we were surprised to find Corydoras eggs all over the tank walls.
<Quite common, if you're keeping these fish well, which would seem to be the case!>
I've read what I could find but I'm still really not sure what to do.
<Depends if you want to rear the eggs.>
We are new fish owners (about 5 months) but we'd like to try and save the eggs.  There is a local fish club so I think we can find new homes for them.
<Good. To be honest, if you're a casual breeder, you're unlikely to rear more than few catfish even from dozens of eggs.>
I've read to scrape out the eggs and put them in a new tank.
<Not scrape; roll! Wait a few hours after laying and you'll note the eggs feel quite firm, like hard gelatine. Now, when that happens you can roll the eggs and they'll fall off the glass. It's tricky, and you'll lose a few, but eventually you'll get the hang of it. Putting something like a flat-edged net or container against the glass underneath the eggs can help catch them. In any case, collect the eggs this way, and pop them into a small container of aquarium water.>
We don't have another tank yet.
<Not a problem.>
What is the minimum size tank we must buy and what else will we need?
<You don't. A breeding trap will do. You can get these for under $5, either a floating one (I like these best) or a net that clips to the side of the aquarium.  Put this in the aquarium, then put the eggs into it. Make sure there's a good flow of water nearby, and if you can, medicate the whole aquarium for fungus (a half-dose of Methylene blue works well) because some of the (usually unfertilised) eggs will likely go rotten.>
We aren't able to spend a lot so this could be an obstacle. Where do we put the eggs exactly, and what water conditions / food etc., are required? 
What else do we need to know?
<Once the eggs hatch, they'll need food. Ideally, you'd use newly hatched brine shrimp, but if you're just starting out and don't mind the loss of some of the fry, then liquid or powdered baby fish food (e.g., Hikari First Bites or Liquifry) will do.>
I appreciate any advice and especially hope you can explain in very simple terms since we are not at all fish experts!
Thanks so much,
Sue
<Hope this helps. Cheers, Neale.>
Re: Corydoras eggs      5/22/12
Thank you for your wonderful advice.  Oh my gosh-- we have babies!  They are in a little net breeding trap inside the tank where the rest of the fish are.
<Well done!>
I will buy the food you suggested. Do we start feeding them right away (or do the eggs serve as food for awhile)?
<You can feed them straight away. Aim to offer multiple small meals per day rather than just once or twice. Most of the food will fall through the net or be washed away, and even if they do catch some food, they can eat only a little bit at a time. Use a pipette or small syringe to release (squirt) small amounts close to the fry rather than just hoping for the best.>
How long do they stay in the breeding trap and when do I need to move them?
<Realistically, 2-3 months. While Corydoras grow fast, and will be surprisingly big by the end of the first month, they're still too small to compete with adults or avoid predation.>
If we were to put one or two with the adults eventually, when would that be? And if we want to give some away, when is that safely done?
<Three months.>
The aquarium store told me not to add Methylene blue to the tank since the babies are in the same tank as the adults.  I trust your advice more so please tell me, should I get some and add it now, with adults and babies in the same water?
<Methylene blue at half dose like mentioned earlier is a very mild treatment and nearly 100% safe with both fry and adults. However, if the eggs have hatched and there's no sign of fungus, you may not need to use it at all.>
Is there anything else I should be asking?
<Hmm… do maybe read here:
http://www.wetwebmedia.com/fwsubwebindex/coryreproart.htm
That's my own experience of breeding Peppered Catfish.>
This has been very exciting for my 11 year old daughter and me.  Thank you for helping us through it!
Sue
<Most welcome. Cheers, Neale.>
Re: Corydoras eggs      5/23/12
I'm sorry, one more follow-up question.  The instructions on the  Methylene blue label are terrible.  I removed the filter in my tank (10 gallons, contains all my fish and a breeder trap with hatched eggs)
<No, you need the filter in the tank! ONLY remove carbon. Without the biological filter, water quality will drop, and rapidly.>
and added 1/2 teaspoon of  Methylene blue to the water. Just one treatment, correct?
<The recommended dose for Methylene Blue is 2 ml of a 1% stock solution per 10 litres (~2.6 US gallons), and done as a one-time thing if you're breeding fish, but repeated every few (2-3) days following a water change.
Methylene Blue degrades within a few days, which is why you can safely add the dose needed for the whole tank each time you do a water change.
Typically, fish breeders don't fuss too much about the dose, and instead add the stock solution a drop at a time, let it swirl around the tank to disperse, and repeat this until the water turns just blue.>
And do a water change when treatment is complete -- when would that be? 
Should I remove half the water in a couple of days?   I've never seen such confusing instructions.  And will the eggs just dissolve eventually?
<Yes, but you can siphon out detritus if you want. A turkey baster is great for this, as it sucks out the junk without scaring the fish (or fry).>
Thanks and hopefully we'll be all straightened out after this!
Sue
<Cheers, Neale.> 

 

Corydoras fry     4/22/12
Hi, WWM crew! I have a bit of  a situation on my hands. I've recently had a surprise batch of eggs from my C. pygmaeus, (my first fish ever to breed in one of my tanks, so exciting!)
<Ah yes!>
 and after a few weeks of improvising and scouring the internet, I've not had any dead fry :D.
Now, yesterday, I noticed several fry swimming around the moss in the main tank, and the parents were ignoring them, so I released the other 17 from the 'breeding' net (actually a shrimp net). Then, I discovered that the C. Paleatus in another tank had laid eggs, and so I collected them and moved them to the  slightly warmer pygmy/shrimp tank. Then I noticed that the pygmies had laid *more* eggs, and I collected about ten more. So, I read that the newly hatched pygmy fry can be eaten by older pygmy fry, but wasn't able to find: How many weeks apart before the new fry will be in danger?
<A month or so, if well-fed... what are you, or are you, specifically providing?>
 Also, will say, one week old fry be eaten by one month old fry, or is it only newly hatched fry that get eaten?
<The smaller, the more likely; most of all just eggs>
Also (this may be a silly question) is there a problem with raising the pygmy and peppered fry together for a week or two? Are the peppers going to grow to eat their little friends?
<This should not be a problem>
I realize the adults can be housed together, but I was taken aback by the big fry eating little fry thing, and can't seem to find anymore info on the subject.
Thank you all for such a wonderful job done on this site by the way.
My 20 (so far) new little buddies and I really appreciate it!
-George
<Congrats! Bob Fenner>
Re: Corydoras fry     4/22/12
Hi again, yes, I am feeding cultured infusoria to the younger and pulverized algae wafers and flake food to the older ones. Although,  the ones I noticed that had survived in the main tank seemed to be growing just as fast or faster(hard to see what exactly they are eating) , so I think my tank might be a big soup of microscopic critters for them.
<Ahh, luckily,  happily so. BobF>
Re: Corydoras fry
Okay, good to know. I just noticed even more eggs laid by the C. paleatus. I guess love is in the air! No complaining, it's an excuse to buy another tank.
<Ahh! These are "stock" fish species... you might be able to "support your petfish habit" by their culture, sale to local stores>
My last eggs have just hatched, so I guess I'll put a few of the new eggs in with the hatchlings. The brand new fry wouldn't eat unhatched eggs would they? Although I imagine they would be nutritious...
<They're likely fine. BobF>
Re: Corydoras fry     4/22/12
Okay, great, off to the hatchery I go! You have a good one. :)
-George
<And you. B>

 

Re: spotted Tatia query + Cory babies 11/1/11
Thanks for all the information. Much appreciated.
<Most welcome.>
It seems that the 3 Tatia I have are all female going by the non-appearance of the male anal fin you mentioned :-( Also, over more time, one of the younger fish is now taking on the appearance of the older browner one, so I am still hoping that all 3 may be the same in the end.
<Cool.>
On a different note, 2 of the Cory cats I have are Venezuela orange, and the other 2 are the common bronze and albino, (one of each). Over the last few weeks batches of eggs keep appearing on the glass sides, some of which I have rescued, and have survived, in a separate tank. I can not possibly consider keeping a lot of these, and it seems such a shame to let them die.
<Quite so. Remove as many eggs as you want, move to a floating breeding trap, and rear those until they're big enough to set loose.>
I think the young are the offspring of the orange cats, as they are always together chasing about, and are seen around the eggs as they appear... they have produced several batches of eggs now.
<Are all varieties of Corydoras aeneus, so will likely crossbreed anyway.>
I have asked my local store if they take in baby fish and the answer is no as they can not then guarantee quality parentage to the buyer, which is a good view point for the buyer, I do agree.
<Yes and no. Many pet stores will take home-bred fish because these are less prone to disease and more likely to settle into an aquarium. However, much depends on how far your retailer trusts you, in other words, what kind of relationship you have with them.>
My question is, how can I dissuade the fish from producing eggs?
<Can't.>
I have 2 Ancistrus red/black in this tank now, hoping they will eat the eggs, but they are only baby and seem to be uninterested.
<Adults will eat Corydoras eggs, and in any case, without specific feeding, few hatchlings will find enough to eat in a community tank, so the chance of any surviving will be low.>
(The store labeled them as L016 but I can find no information.)
<L016 is an unidentified Oligancistrus species. Similar to Ancistrus, but not quite the same. Black fish with white spots. From the Rio Xingu, so above-average water temperature is important (25-28 C usually recommended for Rio Xingu fish) and that makes them poor companions for most Corydoras (which prefer 22-25 C). Soft, slightly acidic water helpful.>
I would like to add that I do have a larger tank (50 gallons+) with other occupants in, where the Ancistrus can live if they get too big for 10 UK galls with the 3 Tatia and 4 Cory cats. Some of the Cory babies will end up in here, when they are large enough not to be eaten by a large Featherfin squeaker!
<Synodontis euptera is territorial but not aggressive, and should be fine with adult Corydoras and Oligancistrus.>
Any help appreciated,
Thanks
CL
<Cheers, Neale.>

Re: Salt and heat treatment of Ich... Water chem./FW DH, chatting re Corydoras repro.   7/14/10
Hi Neale,
<Hello Lu,>
Oh great, my other half mentioned adding a few small pieces of ice in the back overflow part of tank, carefully watching the temp.
<It's fine to do this, and you don't need to be paranoid about water temperature. Provided the block of ice is some small fraction of the volume of the tank, less than, say, one-twentieth, the overall water temperature change will be small. The fish will usually dart in and out of the cold, sinking water under the block of ice, and in many cases seem to very much enjoy the sensation. Danios and Corydoras are two fish types that enjoy this sort of thing.>
Too funny. Yes, on the current and species issue. Cool, so glad about the hardness recipe, can't wait to play the weird scientist and mess with this in a five gallon bucket. I promise, I sure won't add to tank directly.
<Excellent. It is fun, and once you've made a recipe that works, you're set for life.>
I don't know if you have ever experienced this, but I thought it was so neat. My Cory cats are mating, and the females clean the glass, carry the eggs between their bottom fins, and place the eggs on the walls of tank, and the plants. I was blown away, so darn cute.
<It is very cute, and yes, I have bred Corydoras. Some notes and photos here:
http://www.wetwebmedia.com/fwsubwebindex/coryreproart.htm
One of the great mysteries is how the sperm and eggs get together. Males shed their sperm in front of the female, but how she gets the sperm to the eggs is unknown, though one theory is she swallows the sperm, passes it quickly along her gut, and then sheds the sperm onto the clutch of eggs in her pelvic fins a few at a time. Pretty weird, I think you'll agree.
Corydoras catfish are among the most interesting fish hobbyists can keep, and yet so undemanding.>
Of course, after all that hard work, they eat them later, what a hoot.
<Do try rolling the eggs off the glass into a breeding trap. The fry are very easy to rear, by the standards of egg-laying fish at least. I have three generations of them living in one of my community tanks by doing precisely this. Sure, I only rear a few "kittens" successfully, but that's enough if you're just doing it for fun.>
I don't mind, as this keeps fish population down. I feel bad for two of the Cory cats because even though I have provided them with fine sand, two of them have lost their whiskers, it is as though they have no lips at all, poor babies. They seem ok and still eat, they just look pathetic.
<Will soon grow back given good conditions. Technically, it's bacterial decay rather than the gravel that causes erosion of the whiskers. It's just that gravel tends to be dirtier than sand -- contrary to what you'd expect -- and the decaying organic matter on gravel coupled with physical damage to the whiskers means the whiskers erode rather than heal normally.>
Indeed, you are so correct about the butterflies. Again, Neale, it is such a pleasure to email with you, thanks so much and as always happy fish keeping. Be well. Lu
<Good to talk. Have fun! Neale.>

Corydoras Eggs 1/11/10
Dear Neale,
<Rose,>
Thank you for answering my questions several weeks ago about the fry.
<Glad to help.>
I have three fry left of the original 120 eggs and the largest is about 1.5 cm. They are about 15 weeks old.
<Doing a good job! When breeding fish, there's so much to learn and get right, that even rearing a very few of them successfully is a small triumph. Since fish will lay eggs every few weeks given the chance (and the right spawning triggers) you'll have many opportunities to try out new things in the future.>
They were in a breeding net in a twenty gallon long tank. The net did not allow much air flow and trapped debris on it that could not be cleaned off within the tank and made the tank get a bad odor.
<One approach is to have two traps. Change them over each week, and clean the one not being used with warm water and a scrubbing brush of some type (a toothbrush is ideal).>
I did do water changes of sorts in the net to try to counter these problems, but the pollution was still bad enough that I thought it was very bad for the fry. We had discussed letting the fry out of their tiny world before, and I did let the seven of them out when I tried to clean the net with a hose, brush, etc., but I believe nothing short of bleach would work.
<Be super careful with bleach. Would recommend instead things that break down easily and harmlessly: hydrogen peroxide, lemon juice, vinegar.>
Within hours the fry began to go missing and during that time I purchased a plastic breeding trap for livebearers. The stores in this area had only ones sized small, which is considerably smaller that the original net. It is about 5cm by 13cm and 6cm to water level. Since I could only find three fry left I gathered them up into the breeding trap (I did not use the lid or the piece that can be put in to separate the adult from the young).
They have been doing well in there for quite a while now and the vents in the trap provide good water flow and it looks so much cleaner than the net did.
<Cool.>
The plastic traps float, so they are much more convenient during water changes too. The net did not float and attached to the top of the tank with metal tabs that would often fall off and into the tank.
<Yes, have noticed this.>
My experience was that the plastic one is far superior to the net one, but a larger size would be very helpful.
<Agree. I use a net with suckers rather than metal clips, and find it useful.>
I have a second breeding box that has three fry from another later batch and I was pleasantly surprised that even when they were freshly hatched they did not escape through the vent.
<That's the idea!>
Last night one of the original fry must have jumped out of the trap as he is swimming with the adult Corydoras and Blackskirts today.
<Swimming with the big boys, eh?>
Is it possible that the three fry could have their growth stunted/lives shortened by the confines of the breeding trap?
<Not really, no. Since water mixes inside and outside the trap, there's no dangerous build up of metabolites inside the trap that might stunt growth.>
I am trying to decide if I should put the escaped fry back in the trap, or let the other two out also, or leave him in there for awhile and if he survives X amount of days then let the other two out.
<Assuming he doesn't get eaten by the other Corydoras, the main problem is starvation, with small fry needing finer food than the adults. But given sufficient food, Corydoras fry somewhat over 6 weeks of age compete reasonably well with adult fish that aren't going to eat them.>
I would also like to know if it is advisable to keep different generations of fry together in a breeding box, or even add eggs in with fry.
<Again, there's no direct threat, but smaller fish can lose out at dinner time, so you'll want to watch everyone eats normally.>
I'm attached to these cute fish!
<As you should be!>
Thank you, Rose
<Cheers, Neale.>
re: Corydoras Eggs
Dear Neale,
Thank you. The runaway fry still seems to be doing fine and since he is somewhat transparent (albino) I can see that his stomach seems to be full.
<Good.>
I guess I'll leave him in there and see what happens.
<OK.>
About the breeding trap vents and newly hatched fry, I meant that I thought it was designed for baby livebearers which I thought might be much larger on day one (I haven't kept livebearers yet) and so the new Cory fry could
possibly get out or even get stuck.
<Ah, yes, certainly a worry. But I've never found this to be a problem. Fry jumping out of traps and nets is usually more of a thing.>
Luckily, none of them did. The problem with the Blackskirt that was getting picked on several weeks ago was also resolved (for now) when I moved things around in the tank. Just as you said there are new batches of Cory eggs over and over since they got started, every two to five weeks or so.
<Yes, sounds about right.>
If I ever find them in stock locally I plan to get some low light floating plants I have a list of or moss ball or something to put in the tank (after quarantine and maybe a de-snailing treatment).
<Indian Fern is a good choice, and favoured by fish breeders the world over. Snails are actually quite useful in breeding tanks, provided you don't get carnivorous species that would eat the eggs. Among other things they stir up the substrate, consume organic matter, and even promote the growth of infusoria upon which baby fish can feed (Apple snails were very widely kept for this in the past, before powdered fish foods for fish fry were available). So while removing snails might be sensible, don't be too paranoid.>
Thank you, Rose
<Always a pleasure. Cheers, Neale.>
Corydoras eggs 10/22/09
Dear Neale,
<Rose,>
Almost four weeks ago I had a question about Albino Corydoras eggs and you gave me great advice about hatching them in a breeding net there in the main tank. I have been having a wonderful time with them. There were 120 eggs and there are now at least 70 fry visible at any time (don't know how many are hidden under the frame and the seams).
<Fantastic! That's a very good ratio of eggs to fry.>
The fry are now three weeks old. I have the big API water test kit so I am prepared to monitor the water throughout the next phases to detect problems, but perhaps your experience can help me better avoid problems to begin with. Initially I had planned to keep all the new Corys for myself, but there are many more than I expected since most of my Googling found about one-third hatching rates for beginners.
<Indeed. As I say, you've done really well.>
I have already been wondering what to do if I find more eggs, leave them to chance or destroy them!
<If you leave them to chance, they'll be eaten by the next day. But since Corydoras will spawn every few weeks, rearing a batch or two per year is, I find, more than good enough.>
Given the gregarious and bottom-feeding nature of Corys, how many adult Corys can live in a 20 gallon long tank (I have one vacant)?
<Oh, probably ten or fifteen adults around the 5 cm/2 inch mark. Rather more juveniles.>
In an identical tank with seven Blackskirts, how many adult Corys can live in it?
<Maybe ten adults.>
I do weekly water changes of maybe 20% on all my tanks. Since there are so many (some at 1 1/2 cm, some much smaller), I was wondering if it is about time to graduate the fry out of the breeding net.
<Sure. The fry can be mixed with adults once they get more than 2.5 cm/1 inch long.>
I have considered that they should probably have shallow water to surface easily, but am concerned about them having a world so big that it is a challenge for them to find food.
<To a degree, this is a fair concern. But the flip side is if you keep too many growing juveniles in a small (say, 10 gallon or less) tank then water quality becomes an issue, and you'll find fish dying. Since you gave 70 (!!!) to play with, why not experiment with half a dozen in the big tank, and see what happens?>
They were initially fed Hikari First Bites and also brine shrimp, but they have also been introduced to Hikari bottom feeder food and tropical flake.
<A good mix. I've found Hikari foods work well with Corydoras.>
If a 20 gallon will be too large right now, I also have a ten gallon that could be a nursery tank for awhile. Since I have other aquariums going as well, it is a bit more difficult to convince the Mr. that buying more aquariums so I can keep them all is the way to go (yes gentlemen, it does work the other way around sometimes!). Thank you, Rose
<Hope this helps. Nice to hear of your success, and good luck! Neale.>
Corydoras eggs 9/29/2009
Good early morning or late night, I have just found what must be Albino Corydoras eggs in my Cory and Blackskirt Tetra tank. This was unplanned (by me, anyway).
<Nice surprise though!>
I do have extra seeded filters in the tank so it is easy for me to take some of the water and start another tank, and I have brine shrimp to hatch and also Hikari First Bites (I don't know if that works for Corys).
<Does, have used it.>
I read your site (way too much) and I read
http://www.wetwebmedia.com/FWSubWebindex/armcatreprofaqs.htm
but found that this one:
http://www.wetwebmedia.com/FWSubWebIndex/coryreproart.htm was a bad link
<Seems to be working fine now. Try pasting the link straight into your browser and see if that helps.>
Since I discovered these eggs late at night I assume that they would have had time to be fertilized since I read that they usually spawn in the morning.
<Correct.>
I don't trust the Blackskirt Tetras with anything that they can fit in their mouths so I was able to take a fish net and bend the handle so I could cover the eggs with net and pin the handle under the hood to hold it
there overnight.
<A floating breeding trap works fine for Corydoras eggs.>
I think it is interesting that they placed these eggs in an area that the Blackskirts never go to, near the surface, far from the plants, in the corner that gets the most light.
<Whether the Corydoras specifically put their eggs there, or simply the Blackskirt Tetras ate all the eggs everywhere else is difficult to say...>
I don't know what poses the greatest risk, moving the eggs off of the glass or leaving them in there where they can't be treated with something like Methylene blue for fungus.
<Removing the eggs isn't as difficult as you think. Use a finger to gently roll each egg, and the egg will fall down into a net or plastic cap you've placed underneath. While you might lose a few this way for whatever reason, you'll get most of them. Transfer to a breeding trap, and off you go!>
What is the shelf life of such chemicals?
<Good couple of years, at least.>
I ask because if I have any here it is several years old.
<Probably worth a shot, provided it was kept somewhere cool and dark.>
Please forgive me if I have demonstrated a lack of thought as it is quite late tonight and I have been taken aback by the sudden prospect of kittens.
Thank you for your wonderful site, Rose
<Baby Corydoras are fun to rear and highly entertaining. First time around you may lose a lot of them through various things, like not enough food, but you'll likely rear enough to make the whole thing well worthwhile. Good luck, Neale.> 
Re Corydoras Eggs 9/30/09
Hello Neale,
<Rose,>
I would send this as a reply, but I didn't get an email but rather saw my question in the dailies. This morning I found more eggs (at least as many as the other batch), this time on the opposite end of the tank down at the floor in what I would call the Blackskirt Tetra danger area.
<I see.>
So far they have not been eaten and since I have read your answer I am going to go and buy a breeder net.
<Good stuff.>
From what I read here
http://www.wetwebmedia.com/methblueart.htm
I thought I shouldn't add Methylene blue to the main tank so now that I have two batches of eggs would you still recommend that I put them all in a breeder net, or would you say that I should put half in to another tank and treat them?
<Whichever is most convenient. The good thing with fish is they spawn again and again, often only a few weeks in between times. So you can experiment.
If something doesn't work, next month try something else...>
I think the eggs at the top won't be hard to remove and catch since I will have gravity on my side, but the other ones might be a bigger challenge for me. Thank you for answering my questions so quickly, Rose
<Good luck, Neale.>
Re: Corydoras eggs  11/22/09
Dear Neale / Crew,
<Hello again Rose,>
If you don't mind my sharing, I'd like to report on my Cory fry for others like myself that can't find much in the way of beginner stories.
<By all means, share away.>
So, continuing from my other posts, when I moved the small Corys from the breeder net and into the larger tank I counted 74, and this was 40 days since the 120 eggs were first discovered. The filter intakes were covered with pantyhose so they wouldn't get sucked up and they all seemed to be active and finding their food.
<Cool.>
Despite daily partial water changes, the next couple days I found a few dead (various sizes, not just runts) and there must have been many more dead eaten by their peers in the next days as there now seems to be only thirty-some (of varying sizes) that seem to be holding steady.
<This does happen. Breeders wanting lots of juveniles tend to keep the fry in a big tank with no substrate. In standard community tanks, the substrate at the bottom of the tank is enough to harbour bacteria that seem lethal to small fry. For casual aquarists, this is no big deal, since the fun is simply raising a few fry, rather than hundreds. But if you're serious and want to sell the fry, then a tank where you can siphon out dirt from the bottom pane of glass daily seems to be important.>
Back in the original main tank, 40 days after they had the first eggs, the adult Corys had more eggs (over 170) that stayed on the wall for five days until I assume they hatched and were eaten. I guess the parents and the Blackskirts didn't have a taste for eggs?
<Maybe.>
On a side note, today one of the plump Blackskirts has been in a homemade cocohut all day and I have never seen them go in there (the huts are for the Corys). The fish's body looks normal, but I do wonder what it is doing (I assume NOT laying eggs as I have read that they scatter them carelessly).
<Blackskirt tetras (Gymnocorymbus ternetzi) are not the most peaceful tetras in the hobby, and in insufficient numbers can become nippy and waspish. Observe for a few days, and see if this fish is being bullied by its peers, or conversely, is behaving aggressively itself.>
Thank you, Rose
<Cheers, Neale.>
Re: Corydoras eggs 11/22/09
Dear Neale,
<Hello again Rose,>
Thank you for the response today in the dailies.
<My pleasure.>
I should have mentioned that the tank I moved the Cory fry into IS bare bottom for now, because I thought it would be easy for me to spot any dead as they would disappear over the beige sand that I use.
<Very good.>
I didn't know about the potential for substrate to harbor bacteria that could hurt them.
<Seems to be the case. The flip side is that a tank with lots of algae and Protozoans also contains lots of food that newly-hatched fish can eat.
That's what baby fish would eat in the wild. I recently bred some gobies while I was on the other side of the world, simply because the eggs hatched in a tank filled with algae, and the baby gobies found enough to eat.
Indeed, with livebearers, this is the best approach to take. But for whatever reason, Corydoras do seem very sensitive to microbes at the bottom of the tank.>
There are still more than a quarter from the eggs surviving at 56 days in and I take comfort in believing they would fare much worse than that in the wild.
<Heavens, you're doing much better than the wild! One of my marine biology instructors discussed Herrings, which have to spawn within a two-week period of time they can't accurately predict. Too early, there's no zooplankton for the Herring fry to eat; too late, and the population of algae in the plankton are so high they produce toxins that kill the baby fish. Some years no fry will survive, despite the female Herrings producing hundreds of thousands of eggs that season!>
I had mentioned a Blackskirt in the other tank that is hiding in a cocohut.
It is still there after at least 27 hours and has missed feedings.
<Odd. It might be ill, especially given its still not eating. Any other symptoms? Does it look swollen? Are its colours different to the others?
Are its fins raggedy?>
It is one of seven and none of the others are larger (I think it has reached full size).
<A good number... they should be happy.>
When they charge and nip they have always seemed to do so evenly and they are darker than many photos of their kind (even over beige sand).
<As is their wont. These are "boisterous" fish by any standards. If there's space, adding 2-3 more might help if the issue is social. But I'm not sure that it is.>
I'm surprised they don't nip at the Cory Cats as the Cats nearly blunder into them.
<Interesting. Corydoras are always nipped when I mix them with South American Puffers.>
Thank you, Rose
<Cheers, Neale.>
Corydoras Eggs, feuding Blackskirts 11/22/09
Dear Neale,
<Rose,>
Sorry to bother you again, but wanted to say the Blackskirt finally came out of the cocohut and was being chased behind the heater and all over the place.
<By the other Blackskirt tetras? Does sound social, in which case adding more can help. But if they're picking on a weak or sick specimen -- as sometimes happens -- this might not work. You could try moving it to another tank. By itself it might swim about more readily, and if you're lucky, it won't be nippy.>
When the juvenile Cory Cats grow larger I was going to move some of them in with their parents and these Blackskirts so there was already going to be some fish shuffling going on. I am wondering now if I will have to so some dividing and reintroducing of these Blackskirts as I guess the odd fish out would not be happy kept all alone either, correct?
<It isn't ideal, but it is what I'd do.>
Thank you, Rose
<Cheers, Neale.>
Re: Corydoras Eggs 2/12/10
Dear Neale,
<Rose,>
Since I have two batches of fry, one about twenty weeks old now and the other about ten weeks, I have a silly question. They are all different sizes. For example, one of the younger fry is the size of fry that are twice his age. I have only five all together and some of them graduated into the main tank about four weeks ago. Are their prospects of surviving with adult fish determined strictly by their size, or should their age also be considered due to mental development, etc.?
<Strictly determined by size. After about three months, or once they're about 2.5 cm/1 inch long, they can be trusted with adults, assuming the tank isn't too deep (remember, they're air-breathing catfish) and they can get some food.>
Thank you, Rose
<Cheers, Neale.> 

Population Control - Platies and Corydoras
Hi! Hope all is well with the crew members!
I discovered what I believe are a handful of Peppered Corydoras (maybe Albino Corydoras, they are clearish/grey at this stage) fry in my tank tonight.
<Well done! Peppered Corydoras and Albino Corydoras are the same species, usually, Corydoras paleatus.>
After getting really excited, I've turned to a state of worry about the rapidly increasing population. I was under the impression that Corydoras were not that easy to get to spawn?
<My Peppered Corydoras spawn all the time. So no, not that difficult. Other Corydoras species are much more difficult to breed, and some have not yet been bred in captivity. So it all depends, really!>
I certainly haven't been trying after I realized I had enough babies on my hands with the Platy fry. These certainly don't look like my Platy fry usually do, although I do have one bluish/grey Platy (but she is currently
pregnant in my opinion). They don't necessarily look like my Corydoras either, but more so than they resemble a Platy. They are also hanging out in caves and on the floor of the tank.
<That does sound more like Corydoras than Platies.>
In my experience, the Platy fry usually prefer the floating plants up top and would venture out occasionally mid and top level. But then again, I didn't notice any eggs in my tank either.
<Corydoras eggs are usually stuck to the glass and plant leaves, often halfway up the sides of the tank.>
Obviously, I have no real clue who these guys belong to. I am new to all of this (going on four months now) and my current 40 gallon tank that houses the Corydoras and Platies is currently recycling (after a medication attempt and misunderstanding about how long I could turn off my filters).
It seems I am prone to make every available mistake possible in this hobby, so I am still having to do daily large water changes as my ammonia and nitrites are spiking. Anywho, my point is, if even my Corydoras are having kiddos in such a unstable environment, what will the reproduction rate be like when I get everything squared away with water quality?
<Likely similar; in fact, the water changes are a key trigger for Corydoras breeding, because cold water replicates rainfall, which is what makes these catfish frisky!>
I'm having visions of tanks in every corner of my house and as cool as the fish/fry are, I'm not digging that idea.
<I wouldn't worry about it.>
Can you advise my best bet in controlling my population? I've read you can resell them to local LFS, however I would prefer not to do so if I can avoid it as I'm not comfortable with how I see them treat their Bettas.
<Do try posting on forums, such as the one we have here at WWM, or any other that appeals. Most have a "sale/swap" thread, and if you chat with people online, you'll be able to figure out who is a good fishkeeper and who is not. From there, you can offer up baby fish as freebies.
Alternatively, just leave them in the tank. Without specific care, few will reach even an inch in length, at which point they might just start to have an impact on filtration capacity. Thirdly, you can always euthanise fry as you see them. Fourthly, you can observe the tank carefully, and when you see eggs, remove them.>
I recently boycotted any LFS that sells Bettas in a cup and/or tinny tiny bowls. Maybe I should revisit this policy as it seems every store does this?
<Pretty much yes.>
And also, from what I've read, inbreeding isn't a good idea either.
<It's not a great idea, no, you do tend to get a lot of fish with genetic abnormalities such as crooked spines or small size.>
Can you suggest a plan of action for me? Maybe another type of fish that would help keep the fry population down? My PH is usually right at 7.6 and temperature steady at 75 degrees. Any other humane ideas (I'm not even sure adding predators is considered humane)?
<Adding egg-eaters is surely humane; Bristlenose catfish for example should do this rather well.>
I hope this wasn't a stupid question.
Thanks in advance,
Gina
<Well done, anyway! Cheers, Neale.>

Cory fry, reading   12/18/07 Hi WWM crew love your site and work and all your help in the past, if this is Neale I'm sorry for being grumpy to you =\. <He's out for a few days... I'm REALLY missing him this AM> I was cleaning my gravel and everything was going normal when I suddenly panicked when I saw about 8 day old Cory fry. UGH. I wonder how many I kind of you know =\. Oh well so my next hour I spent rescuing fry. <Rescued?> I get eggs all the time usually from my two female albino Corys and my 1 male peppered Cory. Yes they do cross with each other during breeding. Hehe. Well, I only rescued 3 = ( so that made me sad but they are doing fine eating finally crushed flake and such. They are in a container with a bubble maker in with them. Well, I compared all 3 to pictures 2 of them look like baby peppered...but one looks like an albino with some spots. Do I have a hybrid? not sure but will they be fine with this diet and containment? <... is likely a cross... maybe w/in the same species though... Please read here: http://wetwebmedia.com/FWSubWebIndex/armcatreprofaqs.htm and the linked files above. Bob Fenner>

... Corydoras repro... algae/"mold" poor English   12/16/07 hi WWM crew I've been keeping my tank maintained perfectly, its a 25 gallon community tank. but last week I noticed a lot of mold on the bottom so I started cleaning it and I got a snail. this week I noticed even more mold growing on the bottom. so I started cleaning it and I saw baby Cory catfish -.- just my luck probably sucked up a fee of them. so now what can I do to get rid of the mold and keep the babies safe, I probably have about 10 babies also I noticed some small worms wiggling around every once in awhile and fish eating them. Mmmmm? thanks for your help <Greetings. Assuming these are something easy to rear like Corydoras aeneus or Corydoras paleatus, your best bet is to move the fry to a floating breeding net/trap for the first month or so, and then to another tank. Corydoras fry grow quite slowly, but after about 2-3 months they are safely mixed with their parents. Cheers, Neale.>
... Corydoras repro... algae/"mold" poor English... bad to worse   12/16/07 this doesn't answer my question, what's going on with my tank? whys the mold growing and how do I get rid of it? and I cant move the babies since they are good hiders and they are big enough to be with their parents. <Feel free to say "thanks" and extend common courtesies such as using proper spellings, grammar, capital letters, etc. Certainly avoid taking the attitude that you paid for my services and I didn't deliver. The "house rules" for messages to WWM crew are on clearly posted on the FAQ address page, so there's really no excuse for not making an effort to be polite. Your bad manners dealt with, let's turn to your fishkeeping skills. Mould grows in dirty tanks and can't grow in clean tanks. Period. End of discussion. Moulds can't grow on clean gravel or bare glass because they can't find anything to eat there. If your aquarium truly has fungi growing along the bottom of the tank, then you have a lot of organic detritus there for them to eat. So clean and/or replace the substrate and keep in clean as part of your normal maintenance regime. Dirty tanks lead to high rates of fry mortality. When rearing fry "the cleaner, the better". Cheers, Neale.>

My Corys... repro.   11/12/07 Hi. Something just amazing happened, I was watching my new Pleco when I glanced at my Corys and they were in the T position. this is normal because I get eggs all the time and they never hatch, but this is the female that doesn't give eggs. What was weird was the male is a pepper Cory and the female an albino, Is this common? Also I am watching the female and she hasn't put out any eggs, how long does it take for her to give eggs? Or was she just pleasing the male because he is ALWAYS following her around. <Depends on what sort of albino Corydoras you have. Most of the albinos traded are Corydoras paleatus, but some are Corydoras aeneus. Hybridisation between Corydoras species is rare. But if the albino Corydoras is C. paleatus, and the male is C. paleatus, they could potentially breed, in which case the offspring will be regular, not albino, catfish. As for hatching the eggs, this shouldn't be difficult. Be sure and read this: http://www.wetwebmedia.com/FWSubWebIndex/coryreproart.htm . Cheers, Neale>

Hello, I was wondering if you could tell me what I would need to breed Corydoras barbatus.   12/27/06 CJ <In a general sense/way yes. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/callichthyids.htm and the linked files above. You would do well to further look into (the Net, libraries) books on Callichthyid Catfishes... David Sands works are especially notable. Bob Fenner>

Catfish egg-release; dwarf Gourami mouth illness/injury   10/27/06   I am sorry if this is a repeat, but I can't remember if I already sent it. <Well, I've not seen it before, and if it was responded to, you've had received an e-mail...> Hello WWM crew. <Hello!> Your website is an incredibly useful resource, and I have used it on multiple occasions. <Excellent - that's what it is here for!> I have a 20g community aquarium. I thought it would have been done cycling months ago, but the ph is very low. <pH isn't affected by cycling - establishing the nitrogen cycle refers to a spike, then respective decline, in ammonia, nitrite and nitrate...read here for add'l info.:  http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm > I have a pair of platies, a pair of guppies, a pair of zebra Danios, a male dwarf Gourami, and a Corydoras catfish. Because of all the pairs, I also now have about 20 mixed livebearer fry. <Yes, this will certainly happen!> I also have a small amount of aquarium salt, and recently did a water change to help raise the ph. I realize now that the salt and jump in pH (about 5-6)... > 5.0 to 6.0, you mean?! That's a *huge* swing...too much for any fish to handle well. With regards to the aquarium salt, when you say "very little", I assume you dosed according to directions? Presuming this, the catfish (nor anyone else) should be harmed.  It's the pH that worries me...> ...could have easily killed the catfish, but instead, this morning I found about a dozen (the number has since decreased) small white eggs stuck to the filter tube, glass, and on various parts of my Swordplant. <Likely due to stress from the huge change in pH...> I am absolutely positive that there was NO male involved. <It's possible.> The conditions were hardly favorable, I did nothing to trigger spawning... <You actually did - by adjusting the pH so quickly, you stressed your livestock out...could have killed them...> ...though there may have been unintentional conditioning as all my fish have been on a diet of Tetra® flakes, frozen bloodworms, mall earthworms, and live baby brine shrimp (the ones that escaped the fry, that is, whose motto seems to be "eat until you can't swim, and then eat whatever swims to you". <Little piggies!!> I know that it is impossible that the eggs got fertilized, so why did she lay them? Is this normal? Could it hurt her? <The release of eggs itself won't hurt the fish, but as stated above, the large swing in pH could.  Stability in pH (as in temperature) is more important than precision, although 5.0 is very low.  I suggest you look into a product like Aquarium Pharmaceuticals "pH Adjust", add it to your water *prior* to doing a water change, then *very slowly* raise the pH by doing water changes (no more than .01 or so per day. Are you using tap water, or de-ionized or reverse-osmosis/de-ionized water? I use RO/DI, and a 5.0 pH is what the unit makes water at.  Either way, since your pH is this low, I would suggest using a quality supplement to increase it, as described above.  Kent also makes a quality product to accomplish this.> Any feedback would be greatly appreciated. John O. <Hope I've helped.> P.S. One more question: (that is somewhat irrelevant but of equal, if not more importance.) <Shoot!> My male dwarf Gourami has something terribly wrong with his mouth. For a long time, his top lip was swelling up, but he didn't act any differently, so I thought it was nothing. A chunk of the swelling actually came off, and the rest of his mouth is inflamed, falling apart, and growing strange puffy things. He hides a lot and does not make the usual clicking noise when he bites, it is now rather muted  I thought it could have been a number of things: the first thing I thought of was mouth rot, but I didn't want to medicate unnecessarily and endanger the lives of the other inhabitants, or kill off all the plants which have FINALLY rooted. Please help me. I would like to know - 1. What is wrong with my Gourami? <Could be mouth rot, mouth fungus, Lymphocystis (that's my hunch based on your description).  First off, you should isolate this fish into a separate quarantine/hospital tank - you don't want him to pass this along to other inhabitants.> 2. What medication should be used? <If it is Lymphocystis, you can't truly cure it, as it is viral in nature. However, based upon the lesion / "skin falling of" description, I'm concerned about secondary bacterial infections.  You must be sure to keep this fish's water *pristine*, and I'd suggest medicating (in the hospital tank only) with a broad spectrum antibiotic such as Spectrogram.> <NEVER medicate your main tank - this will kill your biological filtration and nitrogen cycle.  Once the Gourami is in QT, again, I think a broad spectrum antibiotic is in order.  Also, you may add MelaFix (along with the antibiotic) to promote regrowth of the fallen off area. 3. What can I do to alleviate the pH problem? <This is addressed above.  Also, the Gourami's immune system was also likely compromised due to the large pH fluctuations...you *must* ensure stability, as described earlier...> Any and all help will probably save a life. <I hope so - hopefully you've caught it in time!> Thanks in advance, John O. <You're welcome.  Hope I've helped.  Jorie>

Breeding Corys, reading   6/28/06 My son has a 10 gallon aquarium with Cory cats.  He has four adults, and we recently lost two due to problems with our filter and water.  The water problem has been fixed, but imagine my surprise when I started cleaning the tank and found a baby Cory cat, about a half an inch long.  We never intended on breeding the Corys, and we didn't even know what sexes we had. <Easy enough to do> I also don't know what the eggs might have looked like or if more will hatch. <Not hard to find...>   The baby is still in the tank with the adults, but should we separate it into a separate tank? <Not necessary> Do Corys usually cannibalize their young? <Sometimes eat eggs, very young, but often ideal parents> And should I expect more babies in the future. <With good care, decent water quality and nutrition, quite possibly. Do take a read on WWM re Corydoras Reproduction. The Google search tool... Bob Fenner>

Corydoras Breeding and Pleco Info  - 02/16/2006 Hi to all the crew at WWM. Thank you especially Mr. Bob Fenner for your advice on the swimming behaviour of my Mochokids. I just have a few other questions please. One of my bronze Corydoras has deposited about 70 eggs on the aquarium glass, will they be safe in the community tank or should I transfer them to the smaller quarantine tank that we have on permanent standby. If so how do I go about moving them safely? < The eggs are best in their own tank. Scape them off the glass with a single edged razor blade. Be sure to use water from the original tank. Add an antifungicide too.> Also I would like to acquire a lemon spotted green Pleco but am not sure if my tank is big enough (4ft) as I have heard some Pleco can grow to approx 18 inches is this the case with the lemon spotted green Pleco. Thank you. Ann < Go to planetcatfish.com and find the Pleco you are looking for. Common names sometimes mean different fish in different parts of the country. This is a great website that can tell you everything you need to know about your Pleco. The trick will be to match up the photos with the exact Pleco you have in mind.-Chuck>

Bronze Catfish disease, reproduction  02/12/06 Hi. I have six bronze cats which have are all happy and healthy. They play in groups in the bubbles and are very active. One of them laid eggs a couple of weeks ago and became very fat again looking like it was about to spawn but died very mysteriously. It was starting to look quite swollen and reddish around the lower belly. Has she died from not laying her eggs? Sorry to bother you but have tried Google with no luck. Thanks very much, Dave. <This fish might have been "egg-bound"... a condition where the eggs don't pass for a few possible reasons... or perhaps became infected in the area. Providing suitable water quality, nutrition avoids many of these incidents, but not all. Bob Fenner>

Pregnant Cory?  12/18/05 First, wishing you all Happy Holidays from Michigan (where there is no doubt of a 'White Christmas'!).    <And to all, peace on earth, good will toward all>   I have six Corydoras leopardus (Leopard Cory's) in a well-established, 50-gallon, community tank along with six Bloodfin tetras, six Black-skirt tetras, one Red Flame Gourami and four Serpae (Red Minor) tetras (will re-think this choice of animal in the future for a "community" FW venture).    <Okay>   The Corys are a particular favorite of mine and I spend a lot of time - inordinate, according to my wife - observing my fish, these especially. Tonight, one plunked himself/herself down on top of a decoration and "refused" to be moved. No labored breathing, parasitic "attachments", discoloration or outward damage/injury. Just wouldn't be budged by me or its tankmates, though some of the other Corys tried. (I've observed the occasional "pause" before in Corys but never on a prolonged basis.)    <What characters at times!>   Before making a panicked lurch for the QT, I reached in and gave the little fellow a shove. Off and, running, with no duplication of this behavior. Time will tell but is it possible that this is an indication of pregnancy? (I've never been a "grandparent" before. :) )      Thanks for your time, Tom <More likely "just dozing" or trying to capture your mind! Bob Fenner>

Fat Cory  11/30/05 Hi! I have a 15 gallon tank with a few goldfish and 2 albino Corys. My landlord rescued the Corys who were abandoned by a previous tenant and gave them to me. They've been living peacefully with the gold fish for many months now. I did notice that one Cory has grown very fat now, fat all around, yet it is still a small fish maybe 1 1/4" long. It's still been very active swimming and eating. Is it overeating or about to lay eggs? I haven't been able to find out what's wrong with it by researching on the internet. Do you know? Thanks! Lea <Corys will breed when given good conditions. If all else seems OK with them then your fish is probably gravid. Don> 

Corydoras arcuatus Hi WWM Crew :) Good day to you all. I have a question concerning Corydoras arcuatus. I've been trying to get my trio to breed and have tried everything I feed them bloodworms 3 times daily mixed with flakes and Tubifex worms. And I get up real early and do 50% water change with 60 degree water to induce spawning and nothing should I continue to do water changes till they spawn? There isn't too much info on spawning these my Corys are 1 1 1/4 inches. Thanks JM <Do check on the hardness of the water you're using for the changes, and make or buy or collect (as in rainwater) as soft a water (other than distilled) that you can here. Also, try not making the water changes for a week or so between two, three days of doing so, and augmenting their diet with more, different meaty foods. Bob Fenner>

Cory Eggs 2/24/04 <Hi, Pufferpunk here> I have a 20 gallon tank with 2 African Dwarf Frogs, 3 Black Skirt Tetras, 1 Scissorfin, 4 Corys and 3 shrimps. The tank is doing beautifully!!! So well that my Corys decided to spawn and have laid about 50 - 60 eggs in the tank. I adopted these Corys about 4 months ago and apparently they like their new digs very much. I love keeping a tank but I was not prepared for spawning and don't exactly know what to do now. I've read that they may eat the eggs and I understand that I only have about 5 days to decide before they hatch. Should I just leave them and take a chance on having live young, remove them or dispose of them? What do people do with the new fish? Sorry to be so naive about this...it's probably just a matter of me making a decision. <What I did, was scrape the eggs off the glass & put them in a breeder net, inside the tank. Not all the eggs hatched, but I did have many fry that I raised to adulthood. Try hooking the net across the output of your filter, so they will get fresh water. ~PP>

Cory cat eggs Hi all, We have a male and female CORYDORAS AENEUS who just laid eggs. We also have a weather loach in the tank who sees the eggs as food. <so will the parent Corys.> So what we did was gently removed the eggs from the glass and placed them in a floating breeder with an air stone because we read they need a lot of aeration. <Good idea!  Actually, I just hung the breeder net inside the tank.  I raised the fry in there, until they were large enough to release.  They ate crushed up flakes.> If you have any hints or suggestions they will be much appreciated. thanks <You're welcome & good luck w/your new babies--Pufferpunk>

Re: Eggs in Tank Well, as of last night, Thursday, there aren't any white spots! I will still hold off on cleaning, just in case. Robyn <If they were Cory eggs you may find the fry huddled under a rock or some other little cave on the bottom. Still think it's more likely the eggs or freshly hatched fry were eaten. Keep an eye out, but don't let the tank go too long Don>