                 
|
|
Corydoras C. Julii and C.
Trilineatus
By Aquariumpages.com
Breeding
Corydoras davidsandsi, Black 1987 By
Allan James
Breeding
Corydoras elegans (Steindachner 1877)
By Allan James
BREEDING THE CORYDORAS (C. Trilineatus or
C. Julii)
In every article or book I have ever
read, the claim is that the Corydoras, C. Trilineatus
and near relative, C. Julii catfish have never been bred
in captivity or are very difficult to breed in captivity
and that’s just not true. They can be bred quite easily
if some of the critical and proper conditions are
created in the tank. You do not need to entirely
duplicate their natural environment with the exception
of some critical factors. So you can stop thinking that
you need to create that near duplicate of their natural
habitat. However, in breeding any fish, foremost in
your thoughts should be to duplicate the “critical
factors” of their natural environment which in turn
reduces the ‘STRESS” levels in the fish you’re
attempting to breed. Something else to keep in mind, in
particular with the Corydoras, is that they generally
will not breed the moment you want them to or exactly at
the time you have created the correct conditions in the
tank. You will need to maintain these proper conditions
over a period of time (called the “conditioning
period”). They will breed only when they are ready. So
expect to put in some effort in maintaining the proper
conditions once you have created or met them. These
terrific little fish need to be coaxed out of their
natural shyness over a period of time in order to get
them to breed.
THE TANK SETUP
To start out and increase your chances of successfully
breeding the C. Trilineatus or C. Julii, begin with a
new tank setup, not that the tank or gravel need to be
new, but you should at the very least break down an old
tank to start over. Thoroughly clean the tank and
gravel. Do not attempt to use a tank setup that has
been up and running for over 6 months or longer. A 55
gallon tank or larger is best but not necessary.
With the Julii and Trilineatus, I have had
far less success with smaller breeding tanks. The size of the
tank, 55 gallon or larger, will help to keep things like
water temperature, water conditions and all other
variable factors stable over time, which as you will see
is critical. Smaller tanks have far greater
fluctuations in the conditions in the tank. For the C. Trilineatus or
C. Julii, a course sand bottom or fine gravel should be
used. Also important is how well the aquarium is
planted. It should be very heavily planted and
throw in some Java Moss or something similar for the
female to lay eggs on. It's best if there are plants in all ranges of the aquarium, bottom, middle
and top. If you can, try to cover about 25-50% of
the surface with floating plants, this will keep the
tank dim or dark in certain areas even with the light
on. It really doesn’t matter if
the plants are live or plastic, so you can use a
combination of both. The key here is to understand that
the C. Trilineatus and C. Julii are a VERY VERY shy
species. With an aquarium planted that heavily, you
won’t see much of them, but that’s the goal here in
getting them to breed. Keep the tank in a low traffic
area of your house.
WATER SETUP
The water “condition” is by far the most CRITICAL aspect
and will require most of your effort in successfully
breeding this species. The water MUST be kept very,
very clean. Most chemical conditions should be
near
neutral readings, so you will need to purchase a
multi test kit like the one from Aquarium
Pharmaceuticals to test the water conditions and levels
of pH, Ammonia, Nitrate and Nitrite, etc. Do not add or
have any salt in the aquarium. You can use a water conditioner
such as Prime by Seachem Laboratories to age the new
water. Initially, of course, your water will be totally
out of wack and it just takes time to get through the
water aging cycle. You can use chemicals to make
adjustments but I prefer to wait and go through the
cycle. Your chemical levels should read and be
maintained as follows:
Nitrate = low to neutral
Nitrite = low to neutral
Ammonia = low to neutral
pH = neutral (see below)
Water temperature = 76- 78 degrees
After achieving the above water
conditions, you must continue monitoring and testing the
water for pH, Ammonia, Nitrate and Nitrite levels and
make any appropriate changes necessary to maintain these
levels at all times over the next several months. Your
main goal here is to sufficiently create a water
environment that emulates their natural conditions. To maintain clean water, use a
minimum of two, perhaps three filters if
necessary. The purpose of the filters is two fold. The
sole purpose here is not just to maintain exceptionally
clean water. One of the conditions you need to try to
create, which will be one of the keys to your success,
is to get the filters to create some water “current” in
the tank. The goal here is to try to simulate a
well oxygenated slow
moving stream. If the tank is heavily planted as
describe above, the fish will have plenty of quiet rest
areas in the tank, most likely the corners, and be able
to stay out of the current until they are ready to
breed. Keep the water temperature steady; do not let it
fluctuate up and down. Barometric pressure is
inconsequential. Some reports say that a partial water
change to drop the temperature a couple of degrees will
induce spawning. While this has some merit, it won't work if the female is
simply not ready. It's very difficult to tell exactly
when the female is ready. (typical of many female
species). A better method to induce spawning is to
combine the above mentioned water change with a little known secret to help condition
the water. Boil some Oak tree
bark (or dead Oak leaves) in 2-4 cups of water.
Boiling the bark will turn the water a nice amber color.
Once cooled and strained, add it to the tank.
The boiled extract supplies humates and
tannin which in turn, emulates the pH trigger in their
natural environment of the beginning of the spawning
season. Other similar methods are
filtering over unfertilized peat, peat extracts and
other preparations containing tanning agents.
THE ENVIRONMENT
Contrary to many breeders’ thoughts is the idea that you
shouldn’t have any other fish in the tank at the same
time. Normally I would not recommend this and only
do so IF you have the time to maintain a great deal of
observation. However, not only do the C.
Trilineatus or C. Julii not mind if there are
other fish in the tank with them, as long as they don’t
bother them and they are a relatively calm fish, but
having “other” fish in the tank helps to reduce their
stress level and bring them out of their natural
shyness. So, in fact, it actually helps for them
to feel comfortable and over come their
fear in the tank. They will breed and lay their eggs
with other fish in the tank! So some very young
guppies may be added. The addition of guppies, helps
to keep them from being "spooked" all the time. The guppies
will also serve to help keep the excess food from
rotting. Over feeding will spoil the water conditions
if the food is left to rot. However make sure you take
out the guppies as soon as possible after eggs are
laid. Make sure you have no snails in the breeding
tank. Be sure also not to have any other bottom feeders
or catfish in the tank. They need some sort of
breeding medium in which to deposit the eggs. Leaving the aquarium lights
on 24/7 may start the growth of
hair algae. Hair algae
is the type of breeding medium they like to deposit
the eggs into. A better alternative may be to use
Java Moss or Java Fern. They will breed during the day with the
lights on; this is why a very well planted tank makes
the difference. As the fish will have dark enough
places to hide or sleep as though the lights were turned off
and yet can come out into the light with them on at all
times when they are “ready” to breed.
FEEDING
One of the biggest misconceptions about "prepping" your
C. Trilineatus and C. Julii for breeding, or any fish
for that matter, is that you "need" to feed them all
kinds of specialty foods. This could not be further
from the truth. Myths like that come from people with
more money than sense in the false hopes that high
dollar foods will somehow turn a normal fish into a
prolific sex maniac. Stick with a main diet of good
quality flake foods (I use Wardley brand off the self at
any Walmart store) and shrimp pellets (Wardley), which
is one of their favorites. Shrimp pellets, like flakes,
will fall to the bottom and stay there for the Cory’s to
eat easily. Feed some live or frozen brine shrimp.
Even the live baby brine shrimp that are not eaten by
the guppies will fall to the bottom. Live foods are not
necessary but live brine shrimp will make it to the
bottom and it is a great “snack” food for the Cory’s, as
they like them very much. Tubifex worms are hard to get
to the bottom because they float, but the Cory’s do like
them as well. There is a special food made for
catfish in pellet form that does fall to the bottom that
I use and recommend. No single one is more important than the other, the point here is to
feed them a "variety" of foods. One food
that is used by a very successful breeder is
white worm.
What they eat prior to
breeding, in fact, is not as important as being careful NOT
to over
feed! Try not to disturb the tank in anyway. Feed 2 to
3 times a day and space out the feedings, as even
feedings can be mildly disruptive to them. Merely
walking past the tank will cause these shy little fish
to dart for cover.
THE
BREEDING CONTESTANTS
I have read that it is somewhat difficult to sex this
species but that’s not true either. The males are not
only less bulky than their female counterparts, but the
females have a slightly darker pink color to them. They
should be fairly young in age, the older they get, the
less likely they are to reproduce. When the female is
ready, she will become very active and will swim all
over the tank, up and down from side to side. A couple
of the males will follow her around gently nudging her
with their noses at a 90-degree angle. Also contrary to
popular belief is that they spend a lot of time and
effort “cleaning” the areas they intend to spawn on,
such as plants. This is just not the case. They don’t
clean much or prepare the spawning areas much at all.
Their spawning behavior, of actively swimming all over
the tank, has simply been mistakenly reported as an act
of “cleaning”, when in fact, it is just part of the
mating ritual. There must be a ratio of 4-5 males to 1
female. Only place one female in the tank at a time.
You may need to experiment with trying out different
females. Remember that if you change females; be
prepared to allow the new female time to acclimate to
the tank. The female will lay eggs everywhere and
anywhere, on the glass, on Java Moss, other plants, all
over. The eggs are small and fairly clear in color. This will take about 3 hours and the number of eggs is
nowhere near the 100 plus reported by some. You may end
up with 30-40 eggs and not much more. I believe a lot
of the mistaken reports have come from people who have
never really bred this particular species, but have bred
other species of the Corydoras family and are assuming
the outcome would be similar for the C. Trilineatus and
C. Julii. |
Breeding Corydoras
davidsandsi,
Black 1987 By
Allan James
his species from the
Aeneus Group is found in
the middle stretches of
the Rio Negro in Brazil
and is a look-alike. It
has the same colouration
as C. metae from
the river of the same
name in Colombia but
davidsandsi has a
longer snout and the
black stripe carries on
into the bottom lobe of
the caudal fin while
C. metae stops short
at the caudal peduncle.
The C. melini
connection has melini
having the same black
body stripe ending on
the bottom lobe of the
caudal fin, but the
stripe separates just
behind the dorsal fin
and continues as two
lines over the back of
the body. The
colouration is also
different with melini
being a dirty white with
black specks to the
edges of the body scutes,
while davidsandsi
has a tan colouration
with no specks. If you
can make all that out I
will explain how 1
spawned this species (C.davidsandsi
that is ).
The picture above
shows the black stripe
running along the ridge
of the back. I purchased
two pairs from different
outlets and placed them
in a 18" x 12" x 12"
tank with aged water,
pea gravel, Java moss,
Java fern and a sponge
filter, but little did 1
know the problems I
would have trying to
spawn them even though
one of the females was
quite heavy. I fed them
my usual, being flake
food, tablets, white
worm, daphnia and
bloodworm (live and
frozen) also undertaking
50% cool water changes
twice a week but 1 just
could not get them to
start. My usual visitors
to my fish house would
come in and the first
thing they would say
would be, "have you not
got them spawned yet?".
This went on for
three months until I
decided to give them one
more try. I placed a
powerhead in the tank
for extra aeration and
then carried out a 75%
water change with part
rainwater and flooded
the tank with white
worm, I then locked the
fish house and hoped for
the best. Yes you know
what I'm going to say,
the next morning 1 found
a total of 14 eggs laid
on the Java moss and
Java fern. 1 then
removed the eggs and put
them into a small tank
with water from the
breeding tank . I used
light aeration, but
three days later only
four hatched as eight
had fungused and two
where not fertilized. I
had to go away for two
days and I lost the fry
due to not being able to
change the water. I
needn't have worried
though for a week later
they spawned for me
again, they laid only
five eggs this time
which I put into my
small tank again, but
with no aeration this
time. 1 also added meth.
blue to the water.
They hatched in
three days, and after
two days I started
feeding microworm as
first food along with
egglayer fry food. I am
doing 50% water changes
every day. The next
spawning was a week
later, this time thirty
eggs were laid. I
watched the spawning
sequence this time which
occurred at 9am. in the
morning. One male chased
the larger female as
they took up the
customary 'T" position,
with the male grabbing
the females barbels with
his pectoral fins and
pushing her very hard,
she then broke away from
him after about eight
seconds, then she sat on
her side for a further
few seconds, then
expelled one egg into
her ventral fins. She
would travel about the
tank with the male
chasing her for what
seemed ages, before she
would lay the egg
usually in the Java moss
but sometimes on the
glass. I noticed that
the other male was
trying to get into the
act, but the dominant
male was chasing him
away, so he would go and
try to spawn with the
other female, but she
was never interested.
I keep the fry
in the small tank for
two weeks, then I move
them to a seven gallon
growing on tank with a
corner filter, doing
water changes every
other day. This is when
I start feeding brine
shrimp as well as
microworm and crushed
flake.
This (out of focus!)
picture above is of an
11 day old fry. They
spawned quite regularly
for me after that, with
six to ten days
betweenbroods. The other
female is also producing
now, so 1 am getting
spawns from anything
between twenty and fifty
eggs from the two pair.
For the record the pH
was 6.8 with the temp.
being 80F during the day
and dropping to 76F
during the night in my
fish house. The water is
very soft in this part
of Scotland at G.H.l.
A lesson I have always
learned from breeding
Corydoras is to have
patience and plenty of
it.
|
|
|
|
Breeding Corydoras
elegans (Steindachner 1877)
By Allan James
his species is the
type species of the Elegans Group, which
involves most of the dwarf Corydoras.
Sexing this species is relatively simple
as the adults are dimorphic with
coloration being the main point, and the
males are more ornately patterned and
have also reticulations on the dorsal
fin, while the dorsal of the female is
usually clear.
I picked out two pairs of this species
from a friends collection, noting
particularly that one of the females was
quite heavy. After getting them home I
put them into an 18in x12in x 12in tank
which I use for breeding Corydoras,
with small rounded pea gravel, java moss
and a sponge filter. I fed my usual
foods, flake, tablets, daphnia and
bloodworm (live and frozen). After about
a week I added a powerhead for extra
aeration and started with cool water
changes about twice a week.
Three weeks after obtaining them, they
spawned for me, with the eggs being laid
on the tank sides and the java moss. The
eggs were surprisingly small, being so
used to the larger eggs of C. metae,
panda and daidsandsi, I
had quite forgotten that the Elegans
Group are decidedly smaller. I had
spawned C. napoensis about six
years ago and I was interested to see if
they were similar, so I looked up my
notes and indeed they were, with the
females of both species carrying about
six eggs in their ventral fins, and
being of the same small size. I usually
take the eggs away, but there were so
many of them and being so tiny, I
decided to take the parents out instead,
I also switched off the powerhead and
they took four days to hatch at a
temperature of 78F. The fry disappeared
into the gravel, so I left them for two
days then started to feed Liquifry No 1
for about three days, as the fry were
very small. I then upped the feeding to
Egglayer Fry Food and microworm.
The kittens at ten days old are about
6mm long (TL) with a dark head and four
spots along the lateral line and at four
weeks old the spots join up to form a
black line. At this moment in time they
become a little more adventurous,
swarming over the gravel and java moss
looking for food. I ended up with about
forty young.
One thing I did notice about the adults
was the females dorsal fins being a bit
ragged suggesting that the males were
being aggressive at spawning times
although I never noticed anything during
my observations, maybe some readers of
this article could throw a little light
on this.
For the record, the pH of the water was
6.5 and a General Hardness of 1.
|
|
|
aquariumsite@aquariumsite.net |
|
|
