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Cory breeding question /RMF
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 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?
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
<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.
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
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
3) What is the chance that a 1m to 1f ratio would produce fertile eggs?
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. 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
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!
Much else written in books, online about breeding this genus. Good luck,
Re: Cory breeding question
I am happy to report that I still have six of the original fry (9 days
old) and they're getting pretty big!
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.
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
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,
I know there are some catfish that do make bubble nests, and that Corydoras
are not among them...
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
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?
<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,
Re: Peppered Cory stopped in the middle of spawning - 8/17/12
I'll follow your advice. Thank you very much.
<Most welcome, Neale.>
TWO BATCHES OF FRY 6/19/12
I have 16 bronze Cory fry in a tank - they hatched about a month
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.
<Most welcome. Do read:
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
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
<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
Thanks again for your help, I appreciate it!
<Most welcome, Neale.>
Corydoras eggs 5/20/12
I hope you can give me some advice.
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.)
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
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
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
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,
<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.
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
<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?
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:
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!
<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
<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
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
<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
Thanks and hopefully we'll be all straightened out after this!
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!)
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
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!
<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
<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. :)
<And you. B>
spotted Tatia query + Cory babies 11/1/11
Thanks for all the information. Much appreciated.
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
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
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
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?
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,
Hello there! Thanks so much for your help in the past, it has all
been very helpful advice!
Almost 4 days ago either my peppered or my leopard Corydoras
spawned. I rescued about 50 eggs, put them in a breeding trap at
the top of the main tank. I removed all the white ones, and now I
am left with some amber brown colored ones, apparently they are
healthy. However it seems that they have been in there awhile and
haven't hatched. I can see a brown lines and what looks like
two black dots in almost all the eggs. Is this normal? If it is
normal how long can Corydoras eggs last before they hatch, or I
are duds? Is there anything I can do to speed the process up,
like raise the temperature or something? Attached is two photos
of the eggs, one is with the light on, the other with the light
off. They appear much darker when the light is off.
<Hello Merritt here. Congrats on being a fish parent! If the
eggs are white that usually means they are infertile. The eggs
that are brown are fertilized and the brown lines/black dots are
the developing fry.
Completely normal. Just make sure the eggs have water moving over
them like placing an air stone under the eggs to move the water
and the eggs usually take 3 or more days to hatch. Just keep an
eye on them and have some fry food ready like LiquiFry or
Microworms. Good Luck!>
Re: Corydoras eggs- 8/20/11
Thanks for the advice!
<Glad to help, Merritt here again.>
Turns out you were right Merritt! I have had about 15 hatch,
sadly a few slipped through the cracks of the breeder so I
removed all the remaining fry and eggs and placed them with
inside a bowl in about 2-3 inches of water.
I equipped the bowl with an air stone and water that they hatched
in. I don't really have a spare tank right now, unless I
moved my African dwarf frogs out of there's, or made another
tank swap, (I have 7 tanks). Anyways, can I raise them in this
bowl jerry rig set up, or do I really need the tank with the
filter and panty hoes etc covering the filter. Or is there
anything I can do to improve this set up? Any suggestions would
be greatly appreciated,
<A filtered water system would be the best setup possible.
What you can try to do is make your own netted container, I use
the plastic mesh for sewing sold a hobby stores. You can hot glue
the material into a shape that can hold your fry safe in the main
aquarium. If this is not for you, you will just need to keep on
the water quality (lots ant lots of water changes) in the small
container because it will get dirty with the constant feeding of
the fry food. The best possible setup will insure the maximum
number of fry surviving to adulthood. Good luck! Merritt>
Re: Salt and heat
treatment of Ich... Water chem./FW DH, chatting re Corydoras
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
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
<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
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
<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.>
Thank you for answering my questions several weeks ago about the
<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,
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.
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
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
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
<Again, there's no direct threat, but smaller fish can lose out
at dinner time, so you'll want to watch everyone eats
I'm attached to these cute fish!
<As you should be!>
Thank you, Rose
re: Corydoras Eggs
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
I guess I'll leave him in there and see what happens.
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
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
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
<A good mix. I've found Hikari foods work well with
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,
<Hope this helps. Nice to hear of your success, and good luck!
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
<Does, have used it.>
I read your site (way too much) and I read
but found that this one:
http://www.wetwebmedia.com/FWSubWebIndex/coryreproart.htm was a bad
<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
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
<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
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
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
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
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
So far they have not been eaten and since I have read your answer I am
going to go and buy a breeder net.
From what I read here
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
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,
<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
<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.
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
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?
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
Thank you, Rose
Re: Corydoras eggs 11/22/09
<Hello again Rose,>
Thank you for the response today in the dailies.
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.
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
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
I had mentioned a Blackskirt in the other tank that is hiding in a
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
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
<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
Thank you, Rose
Corydoras Eggs, feuding Blackskirts 11/22/09
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,
<It isn't ideal, but it is what I'd do.>
Thank you, Rose
Re: Corydoras Eggs 2/12/10
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
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
<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,
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
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
<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
<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
<Pretty much yes.>
And also, from what I've read, inbreeding isn't a good idea
<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
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,
<Well done, anyway! Cheers, Neale.>
Corydoras, repro. 07/28/2008 hi there, About a week
ago my albino Corydoras were laying eggs and I was able to
harvest some. They hatched by now and are still living off their
yolk sacs. It seems a couple of them got stuck in their egg
shells with their tails poking out. Can I do something to help
them to get out? I am afraid that they might eventually
suffocate. <You can gently roll the eggs about a bit with your
fingers, or better still, squirt them with a pipette. But the
"kittens" should find their way out eventually.>
They are in a little container that floats on top of the main
tank where the parents are living in a community with other fish.
I do water changes once daily with the water from the main tank.
I have done this before but never had the problem of fry stuck in
the shells. <Does sometimes happen, and usually the fish come
out fine.> Thanks for your help Silvia <Good luck with the
babies! Cheers, Neale.>
Re: Corydoras, repro. 7/30/08 hi Neale, thanks
for that. three of the four came out soon after I got your answer
but the other one was stuck longer. I was afraid to roll the egg
in case I could damage the little guy inside. the other problem
was that there was still an empty shell stuck to it. I tried to
squirt water into the empty shell which gave the little one a bad
roller coaster ride but later it came out on its own although it
looks a bit disabled. I will see how it survives. thanks again
Silvia <It's the nature of egg laying fish that some eggs
won't develop properly. Such fish have evolved to produce
lots of eggs to compensate for the low chances of survival for
each egg. You will likely lose quite a few fry over the next few
weeks for various reasons; unless you're a serious breeder I
wouldn't worry too much. Even if only one or two survive per
batch, that's rather better than would happen in the wild!
Good luck with the kittens, Neale.>
Re: Corydoras 7/31/08 hi Neale, one or two
sounds really very little to me. <That's how Mother Nature
works. If a pair of Corydoras produced more than a couple of fry
that reached maturity, we'd be knee-deep in them pretty darn
fast. Darwin worked this out using elephants. He showed that even
allowing for the fact elephants breed extremely slowly, if every
baby elephant survived, there'd be 15 million elephants
within 500 years. I'm not saying you should aim for this with
your breeding projects, merely resigning you to the fact that not
every single baby fish can or will survive, and in the big scheme
of things it doesn't matter.> as I mentioned before I have
done it before, I just didn't encounter this sort of problem
before. usually I have about a survival rate of 75% after
hatching for the Corys. this time I lost already about 60% of the
eggs before hatching. <Many things may be happening here.
Fertility declines with age in many species, and inbreeding also
reduces fertility. So if you're crossing siblings for
example, you can't expect to have as many fry, or as many
viable fry, as you would were you crossing unrelated wild-caught
fish. Diet and water chemistry may be factors as well.> when I
started harvesting the eggs the female was already laying eggs
for some 4 hours and was already pretty exhausted. the earlier
laid eggs were already eaten by the rest of the community.
that's life :) <Yep, that's how my Corydoras breed,
and the pufferfish follow them around snapping up the eggs like
popcorn. I'm lucky if I rescue half a dozen.> I assume
that some haven't been properly fertilized and some
didn't develop right for one reason or another. <Could
well be, but see above.> even after so many times I always
find it amazing to watch the fish lay eggs, and than those ones
not been eaten, to hatch and grow. much better than TV :)
<Would tend to agree, being a person who doesn't have a TV
set but does have three aquaria and a pond!> cheers Silvia
<Please do write with capital letters in the right places next
time. Normally we send messages back for re-typing if they
don't. But I was feeling nice. Anyway, good luck,
Re: Corydoras 8/2/08 Hi Neale, Sorry about the
capitals. It's just a habit. A bad one I have to admit but
thanks for being nice :) <No problem.> Good old Charles was
right with a pair just to be replaced with a pair. In theory that
is. <Ah, he was simply making the point that without
predation, disease, competition, starvation, etc. populations of
any organism have the potential to increase exponentially. What
he wanted to make clear is that something happens that prevents
this, what he called the 'struggle for life'.> In
reality it doesn't work like this since homo sapiens has
it's hand in it. We seem to be able to wipe out many species,
sometimes before we even discover them. Most of that due to
irresponsibility, disrespect and out of ignorance. The Australian
Government introduced Gambusia into the river systems to control
mosquitoes, ignoring that we have the best mozzie control already
with our beautiful rainbowfish. It has devastating effects on all
native wildlife. When we are going out to do surveys of the
creeks and rivers we sometimes find bodies of water only with
alien, non native fish. We means members of ANGFA (Australian and
New Guinea Fish Association, check out our website
www.angfa.org.au) . The other end of the scale are people who
keep or release predatory animals into an environment that they
are not native to. My garden is abundant with wildlife but I
often fear for them because my neighbour is not willing to keep
her cat inside. Cats are introduced to Australia and I keep mine
inside all the time. <I know a few people who are in ANGFA,
and they do sterling work. Bruce Hansen wrote an excellent
chapter on Aussie fishes for my Brackish book. I'm glad you
keep your cat indoors. As a cat lover, I've always felt
guilty about the death toll cats inflict on wild birds. They are
Nature's perfect killing machines, and in environments
without predators and competitors, they can (and usually do)
cause major problems.> Back to the Corys. Being a scientist I
am happy having more than two surviving which might help to keep
the wild population survive. Especially since specimens in
captivity don't have the life span they could have. I
remember a friend buying a sterbai because she liked him. I tried
to point out that he needed company but she thought he was fine
since he came out feeding. <Sad.> I showed her my Corys who
are all over the place during the day but it didn't make a
difference. She only had him for some nine month. Mine are now
about five years old and still happy. The female albino looks
like she is fattening up again only after two week since she laid
eggs. The kittens are doing fine. Using the word kitten is very
unusual for me. I know that the English and the Americans are
using it but if I use it here I get weird looks. <What else
you call a baby cat but a kitten?> Cheers Silvia <Cheers,
Re: Corydoras... larger issues... 8/5/08 Hi
Neale, <Silvia,> I am probably not the average person. I
read Darwin but I don't own it. But that was some 30 years
ago and I noticed that I often read things others wouldn't
and don't read what they would. I am a geologist but
haven't worked in the field. You could say "conflict of
interest". I didn't want to be in a position where, say,
I had to sign off on a big dam from a geology point of view and
disagree because very old historical heritage would be destroyed
or a habitat for fauna or flora. Initially I wanted to do
ethology but the lecturer put me off when he came in with a
bucket full of baby sharks for dissecting. I was not keen on that
part anyway but when he said that they are ONLY sharks I lost it.
I happen to love sharks, so that was the end of it. <Too bad.
It's a common problem at university that you get exposed to
science through the interests (or biases!) of the lecturers.
Where I did my zoology degree most of the people studying
invertebrates were doing so from the perspective of invertebrate
pests and parasites. I got so cross with the lack of balance I
ended up complaining to the head of department! But the reality
is that most invertebrate biology is done from precisely those
aspects. Most of the money in insect research is in pesticide
development or malaria transmission or whatever. Most of the
people studying nematodes are parasitologists, and so on.> I
worked for an environmental organization I helped to found after
I left uni. Due to various reasons we moved to Australia some ten
years ago. And here is where I can make you again jealous, not
really on purpose though. We live about 20 minutes away from the
beach. So I have good access to estuaries and mangroves but I can
assure you crocs are not a problem down here. The Gold Coast,
that's where we are, has a lot of canal frontage developments
and they attract bull sharks. I wouldn't want to mess with
them, though. We didn't choose this area on purpose. My
husband just happened to get a job here. <I'd tend to
treat Bull Sharks with a certain degree of caution, too! They do
of course swim into completely freshwater habitats, and likely
account for most shark attacks in rivers.> I was never
involved in fish keeping till my children joined the science club
a teacher offered after hours. I joined as well in the hope to
train my English skills. It turned out that the teacher was not
very knowledgeable. She asked the children one day to bring in an
empty 2l (~1/2 gallon) juice bottle to make an aquarium. She
supplied the sand, the weed and the fish. I can't remember
what the weed was but the fish she identified as guppy. Her
recommendation was that they can find more in the drains or to
release it once they don't want it anymore. I got a book
about the wildlife around this area and identified the fish as
Gambusia. Little did I know about the laws. Later we went fishing
with the kids under a nearby bridge where the river is close to
the sea which means it is brackish. <A-ha! Brackish water is
often superb for catching small fish because so many marine fish
lay their eggs there, or spend their first few months there as
juveniles.> We found tiny Monos and scats which we kept.
Unfortunately we kept predatory "shrimps" with them. I
later brought the Monos to a pet shop because they outgrow the
tiny tank and I had no idea how to create a brackish water
system. The guy from the pet shop sold them in his marine
section. At that time, when I started to explore fish shops, I
was taken by the tropicals around. You hardly find natives in the
shops and often only in the feeder fish section. <!!!> It
seems people are more drawn to the "exotic" ones. Ours
are only exotic to others. But I have to agree what we have in
our rivers here is amazing and can match any South American or
Asian. But isn't it that the average people want a piece of
exotic in their living room, like an exotic place where they
would go on their holiday? My experience is that people often
don't appreciate what they have around mostly because they
don't know any better. <I would agree with this.
There's also legal complexity, making it difficult for
someone who is inexpert to know where they can catch their fish
or which species they can keep. Simply finding habitats with
small fish isn't always easy, and then you have the problem
of identifying the fish and obtaining information about their
diet, social behaviour, etc. But on balance, I do agree that it
is somewhat bizarre how little native fish are appreciated in
many countries. Here in the UK we have a lovely diversity of
marine fish and invertebrates thanks to the confluence of cold
and warm water currents. We even have seahorses! And yet people
very rarely keep British marine species in aquaria.> We
didn't go for holidays for years. After I joined ANGFA we
started do go to the field trips and it is a very nice holiday
for us. We are together with nice people, go to places where we
wouldn't go otherwise and see nice environments. For us these
are exotic places, too. Another field trip is coming up in two
weeks and I am looking forward to it. <Cool.> I love to
have the geckos in the house because they take care of the
cockroaches. "Natural pesticides". I don't like to
spray with the fish tank around and I don't like to do it
outside neither. I use the weeds to feed the guinea pig. My
experience with Ancistrus is that I have a much better output
when I leave him to do the work rather than hatch the eggs
without him. <Broadly yes, when fish are left to rear their
eggs, they tend to do a very good job, oxygenating them and
removing fungused ones more delicately than we can manage. There
are some species though where inbreeding has short-circuited
this, most notably Angelfish.> Cheers Silvia <Cheers,
eggs...are they viable? - 7/2/08 Hi there! Neale, if
it's you, I'll be delighted, because this is an offshoot
from a conversation we had a little while ago. You had given me
some fabulous advice (as usual!) regarding keeping golden wonder
killifish with platys and Corydoras without a heater. Thanks so
much for that. <It is indeed me; hello again!> I haven't
yet gotten any new fish, except that I did move four of my bronze
Corydoras from another tank to this new tank, so they could be one
happy bunch (six in total, four C. aeneus. and one C. metae and one
C. julii). Well, it seems they are happy indeed, because to my
surprise, when I turned the tank light on this morning, I saw eggs!
Not to mention a bunch of frolicking Cory cats, which they have
been doing since the morning after I moved them all. What I
interpreted as playfulness, must have been spawning
behavior...although I have to say, I have not done anything
particularly special for them. They've been eating meaty
sinking pellets, veggie wafers, and some sinking foods like
Aquadine crisps and New Life Spectrum pellets. I am not sure if it
they are eating the bits of Nori I am giving them (or if it's
the Malaysian trumpet snails making it disappear) but it gets
offered about three times a week. <All sounds good. Corydoras do
indeed spawn in the morning, and if they're happy, many species
will spawn in the community tank.> I have also been changing 5
gallons of water twice a week. It's a 29 gallon tank, and the
temperature is between 77-80 degrees, as this is what the house is.
The water parameters are: Ammonia - 0 ppm Nitrite - 0 ppm Nitrate -
<10 ppm pH - ~7.8 alkalinity - 300 ppm hardness - between
150-300 ppm (sorry, it's a strip) <All sounds fine for
Corydoras.> I have re-read your article about breeding Corydoras
paleatus, as I was especially interested in seeing a picture of the
eggs. Everything I've read says that viable eggs are amber, and
when they are white, they are no good. Certainly your C. paleatus
looked amber, as I would expect. Well, these eggs are definitely
white - but they seem soft and supple, not hard and crusty, like
the gold ram eggs from a few years back, that I remember that were
not viable. <The eggs start off white when laid, whether
fertilised or not. Over the next day or so, they change colour.
Fertilised eggs become greyish. Unfertilised eggs stay white.
Moreover, after a few days the unfertilised ones become covered
with fungus threads and need to be removed (a small pipette or
syringe is ideal). Also remember the eggs are VERY soft immediately
after laying, and it takes a few hours before they become hard
enough to roll off the glass and into a floating breed trap or
whatever (I use small plastic cartons with holes drilled into them
for water to flow in and out).> To further add to my confusion,
the posts that I have read on various forums have had pictures of
eggs that look white, just like mine, but these seemed to have
hatched successfully. <Don't worry too much about the
colour; just remove them all as soon as you can, and then remove
fungused ones as you go along.> I have a hopeless camera with a
broken LCD (but I can't bear to throw it away, as I spent way
too much on it before it broke!) so I cannot get sharp pictures, as
I am shooting blindly without an ability to adjust the settings
much. The picture I included was about the best I could do.
<Looks quite normal to me.> Can you tell from the picture if
these eggs are "still good"? I have not observed them
eating them, although I am guessing that Corydoras are not much for
egg eating. <Not sure the Corydoras will eat the eggs, but some
snails will (not sure if Melanoides do) and certainly most other
fish eat them.> Naturally, I would love to see some kittens...as
you have said, they are sickeningly cute! I have a feeling this
time isn't going to be "it", but if you have any
additional tips for conditioning them and rearing them, I would be
all ears. Going by your article, it seems I will know in a few days
whether these eggs were viable or not, but of course, I can hardly
stand the wait. <All else being equal, by the time you read this
message it should already have become clear which eggs were
fertilised and which were not. It's a bit of trial and error
really, but Corydoras lay eggs every couple of weeks if you let
them, and before long you will have more kittens than you know what
to do with!> Thank you ever so much in advance! I can honestly
say, I don't know what I would do without WWM. As Sinead
O'Connor once sung, "Nothing compares..." Yours
truly, Nicole <Thanks for the kind words! Neale.>
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>
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.
... 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".
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
Albino Cory catfish 12/8/06 Hi. I have been
searching everywhere for some pictures or a detailed description of
just what a freshly hatched albino Cory catfish looks
like. Do they kind of crawl around on the glass for a little
while before they start swimming? <Mmm, not on the glass... eggs
might well be laid there... wiggle, freely once hatched out... on the
bottom... in slight depressions, in a grouping...> I hope you can
help!!! Thank you for your time.
<Have seen such images in books on Callichthyids, Corydoras
species... If you are seeing something crawling on the glass...
it's not a catfish. Bob Fenner>
Re: albino Cory catfish
(second attempt to respond) <Thanks Tom> 12/9/06
<<Hi, Lyndi. Tom>> There was no answer to my question.
<<Ill try to re-post Bobs response for you>> Albino Cory
catfish Hi. I have been searching everywhere for some
pictures or a detailed description of just what a freshly hatched
albino Cory catfish looks like. Do they kind of crawl around
on the glass for a little while before they start swimming?
<Mmm, not on the glass...wiggle, freely once hatched out...on the
bottom...in slight depressions, in a grouping...> I hope
you can help!!! Thank you for your
Lyndi <Have seen such images in books on Callichthyids,
Corydoras species...If you are seeing something on the glass...it's
not a catfish. Bob Fenner> <<Tom here again. Do a Google
search (Images) for 'Albino Corydoras fry', Lyndi. Scotcat.com
has a nice image of these. (Would have included the link for you but it
was too long to fit in this format.) Hopefully, this will find its way
to you this time.>> Lyndi <<Tom>>
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
> 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 TetraÂ® 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
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>
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
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!
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.
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
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>