irst described by Regan in 1912
Corydoras melanotaenia originates from Rio Manacacias
a tributary of the Rio Meta and from various other locations
in Colombia. Body colour is bronze with a yellowish sheen.
What catches your eye are the clean fins with bright golden
/orange colouration. This colour is more pronounced when
the fish are in good condition or ready for breeding.
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. (It’s 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 didn’t 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
I’m not too sure what to do about that for the best,
I think I’ll 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 I’ll 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.
