fter reading an article on the internet
by Kristian Adolfsson "Dry & Rainy Seasons Tank"
I decided to set up similar conditions in the hope of
my wild caught C. xinguensis breeding. (3 males,
Description:C. xinguensis are from the
Rio Xingu Estado, Mato Grosso area of Brazil. Base colour
grey, dark spots cover the body down below the level of
the lateral line. Lower body and belly region plain grey.
On close inspection spots can be seen on the dorsal and
pectoral fin spines, caudal fin also has light spotting. Size
Breeding Tank & Maintenance:
Tank 18"x 8"x 8" with a small glass trough
8"x 2"x 2" placed to one side of the tank.
This contained silver sand and planted with Indian Fern.
Filtration: Air-driven sponge plus box filter filled with
ceramic rings and a small amount of coral gravel to stabilise
the pH of 6.5.
Feeding: I try to feed my fish at least twice daily
with a good varied diet consisting of the following, Tetra
Prima, frozen bloodworm/ black mosquito larvae and live
Preparation to Breed (Stage 1)
I didnt stick rigidly to Kristians plan but
used the basics and I started by reducing the water level
by 10% every two days until the volume of water had been
reduced by 50%. By this time the plants were just below
water level. I also reduced the amount of feeding, some
days no food at all. Air flow into the filters also reduced
to a very slow flow. These conditions were maintained
for the next 21 days (no water changes were carried out
during this period.) Stage 2:
I began reversing the process by adding fresh water, same
pH and temperature values at the rate of 10% every two
days. Feeding and filtration was also increased at the
same time until the tank was back to normal. I again increased
the feeding along with air supply to the filters giving
even more water movement to the tank in an attempt to
simulate nature during the rainy/flood season.Seven days
later I checked water parameters, 73F/23C, pH5.8. I decided
to carry out a 50% water change using water of 50F/10C,
pH6.9. Once tank had settled the parameters were 61F/16C,
pH6.4. The tank was then left alone to let things happen,
if they were going to happen.
First eggs appeared five days later on the bottom of the
tank. I decided to leave them in the hope of more to come.
The following day I removed the six eggs and placed them
in a 4" cube show tank as I feared the adults may
be egg eaters (I soon discovered that my fears were unfounded).
C. xinguensis eggs are very small, less than 2mm in
size, sticky to the touch. Initially light sandy colour
turning to dark tan during the 4 5 days it took
them to hatch (73F/23C). The following day there were
two more eggs on the floor of the tank, while I was picking
those up I brushed against the Indian Fern and more eggs
fell from the plant leaves. Inspecting the plants I discovered
over 40 eggs sticking to the underside of the leaves,
some single eggs, some pairs but never anymore than two
eggs together on the same leaf. Unfortunately 60% of the
eggs were white and consequently proved to be infertile.
What I did discover while rooting about with the plants
were fry darting around the plant trough, proving the
adults do not eat either eggs or fry.
Fry:When the eggs hatch the fry are a grey ball
with a tail, 2mm total length.
Day 2 they were free swimming. Feeding for the first two
days with diluted Liqufry, followed on day three with
microworm culture. Very soon they were eating newly hatched
brine shrimp, fed little and often. 50% water changes
were carried out daily using water from the breeding tank.
Five days old the fry were starting to develop some speckling
across the face
and head. Seven days old the spots were over the face
and down their back, they now resembled Corydoras
catfish. At this stage the fry were transferred from the
4" hatching tank to a 7" cube with a sponge
filter. Also added in this tank a piece of weighted Indian
Fern, this provided refuge for the fry. As they progress
they will be moved to a larger tank. The original fry
were removed from the parents tank, within ten days more
fry, approximately two days old, were siphoned out by
accident while doing a water change. Any further fry in
the parents tank will be left there. These will be monitored
as to their progress, comparing them with the 25 fry that
were removed as either eggs or fry.
Updated January 2001
The above fry all did well some were past on to friends
sold to one or two local aquatic shops and some were even
sold at fish auctions to the true aquarists who attend
the shows / auctions. I was also awarded a First Time
Bred & Shown Certificate by The
Federation of Scottish Aquarist Societies for breeding
these Corydoras catfish. The original 5 adult fish
were past on to Allan James [Scotcat] who also
has had some success in breeding them, the fry that I
kept were left in the same tank since April 1999 and were
given no special treatment, they were just left to grow
up while I tried to breed some other species of Corydoras,
with some success I may say, in fact I have bred 14 other
species of Cory's since I first bred C. xinguensis.
Yes I did say since I first bred them because what were
the fry are now producing fry of their own, not that I
have done anything special to get them to breed I just
happened to spot some small fish in the tank, I say small
fish not fry because they had all the markings of the
adult fish but were only about a third of their size.
This may help prove that F1 fish are easier to breed than
wild fish or is it just sheer luck?