I bought the
fish at Huddersfield Aquatics 6th March 1999, on
one of our club raiding trips south of the border.
This is an excellent outlet that caters mainly for
cichlids and catfish species, all wild caught. Four
males (3.5cm) and two females approximately 5cm
body size were purchased at what I thought was a
bargain at £2.50 each.
When I returned
home I set them up in a 45cm x 30cm x 30cm quarantine
tank. Temperature 22c, pH 6.5. Filtration was by
an air operated Bio 45 sponge and a corner box filter
filled with ceramic pipes and crushed coral (this
prevents the pH from dropping too low). Tank also
included a small glass trough filled with fine sand
and planted heavily with Java fern. Java moss was
weighed down and placed on top of a piece of slate
(10cm x 15cm). On the slate I had attached
small feet, this allowed the fish a hiding place
and some security as I found them to be very skittish.
They were fed at least twice daily on a mixed diet
of live whiteworm, grindal worm, Tetra Prima &
Tetra Tabi Min.
The fish were
maintained in the above conditions until 4th July
1999. I then re-located their tank to a higher position
in the fish hut, doing this automatically increased
the temperature by two degrees as the hut is space
heated. I let things settle down for three weeks
and then decided to have a go at getting them to
breed. (Its the old story, you talk to other
aquarists who say they have bred Corydoras melanotaenia
years and years ago without any problems, but
they never really enlighten you as to how they did
it). I was doing my weekly 25% water changes to
all my tanks, when I got to the melanotaenia
tank. I did a 40% change using water straight from
the domestic supply, pH 8.3, temperature below 16C. Fortunately
this had no adverse effect on the fish, quite the
reverse as 72 hours later (29th July) they had spawned.
Water parameters at time of spawning were Temp 20c
- pH 6.9.
Spawning:
Day 1. The first eggs I found when I went out to
the fish hut to feed the fish 6.30pm. Eggs
are ivory in colour and measure 1.5mm. These had
been placed at two different sites. Site one, was
on the front glass about 3cm from the water surface
approximately 150 placed in a group 3cm.in diameter
with the eggs on top of each other, in the same
manner Corydoras barbatus lay their eggs.
The second site had double the quantity of eggs,
laid in the same way, the only difference being
that some of the eggs were caught up in some Java
moss and only 10cm from the bottom of the tank.
For the purpose of this experiment I divided the
eggs into three separate show tanks with water from
the breeding tank. An airline was added with slow
turnover to give slight water movement and treated
as follows:
Site One:
spawning (surface) small amount of methylene blue
was added and then removed after 30 minutes by a
95% water change using water from the breeding tank.
Site Two:
spawning (bottom) I divided into two separate tanks
and labeled them Site 2 and 3.
Site Three:
eggs were left as they were, with nothing added
to the water.
Site Four:
methylene blue was added and left for 12 hours and
then a 95% water change was done the following morning
using water from the breeding tank.
Day
2. All eggs
had now changed colour to light tan, some were eyeing-up.
Only six eggs fungused in all of the show tanks,
these were removed.
Day 3.
10am. I did a water change to all three tanks after
I removed a total of six white fungused eggs.
Day 4.
90% water change was carried out out in all small
tanks, removing a couple of bad eggs. By the evening
most of the eggs had hatched
Day 5.
Water changes to all tanks removing any shells
or dead fry. The fry from lot 2 had started
to die off and this had a knock on effect, by the
time I returned later in the afternoon all fry from
lot 2 were dead.
Day 6.
Still keeping lots 1 & 3 separate I transferred
the fry into larger tanks (20cm x 12cm x 12cm) Bio-foam
45 sponge filter added. Feeding started with microworm.
Prior to each feeding 50% water change was done
using water from the main breeding tank.
Day 7. All fry
were looking well, and feeding now was alternated
between microworm and newly hatched brine shrimp
ensuring 50% water changes where done prior to each
feeding.
Day 10.
I transferred the fry to 30cm x 20cm x 20cm tanks
and they were fed as much brine shrimp as they could
eat with a few feedings of grindal worms. Water
changes were stepped up accordingly.
Day 14.
All fry were moved into the same tank (45cm
x 45cm x 30cm). I stopped feeding brine shrimp and
concentrated on feeding grindal worms, Tetra Prima
and Tetra Tabi Min.
The fry were now beginning to look like the adults,
the only difference being the fins had not coloured
up.
Day 30. All
fry were moved to 1015cm x 45cm x 30cm tank. Trickle
filter filled with ceramic pipes and crushed coral
powered by Fluval 4 internal filter. It is a very
rewarding sight to watch 200-300 Corydoras fry moving
about the bottom of the tank on the lookout for
food.
Summary
I normally like to keep eggs and fry with the parent
fish, I believe fry grow bigger and faster in that
environment. On this occasion I was quite glad that
I did remove most of the eggs because I have never
seen a single fry in the parents tank. I know I
didnt manage to remove all the eggs at the
beginning therefore from my experience with C.
Melanotaenia I have observed that they are egg,
and or fry eaters. As to the experiment with methylene
blue Im not too sure what to do about that
for the best, I think Ill stick to the method
of breeding corys that I have used quite successfully
for the last few years, only changing things if
the fish are a new species to me. If I do happen
to get them to spawn Ill normally remove most
of the eggs and hatch them as above until I know
the adults are not going to eat the eggs or fry.
This article
was written for Paisley & District Aquarist
Society, Catfish Study Group UK (formally The Nothern
Area Catfish Group) and Allan James' website ScotCat.