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NFC: Banded Topminnow breeders club report
THE BANDED TOPMINNOW, Fundulus cingulatus
David M. Schleser
310 Appian Way
Dallas, TX 75216
214-943-2025
e-mail: natimg at flash_net
In mid April 1998 I was fortunate to obtain two males and three females
of the pink form
of Fundulus cingulatus, the banded topminnow from Robert Rice. After
quarantining
them indoors for three weeks, they were all moved into a 250 gallon
outside fiberglass
pond that was heavily planted with both floating and submerged plants,
including
Ceratophyllum (hornwort), Ergeria densa (anachris), Cabomba sp., and
Azolla sp.
From my experiences with the related golden-ear killie, F. chrysotus,
and various species
in the starhead killie complex, I expected that within virtually no time
that this small
pond would be crammed with young banded killifish. It should be
mentioned that this
species is much less of a “topminnow” than many others in its genus, and
like the
golden-ear killie, spends considerable time in mid water or near the
bottom searching for
food items.
By mid May the females were obviously filling with eggs and the males
were exhibiting
behaviors of both dominance and courtship. I fed them daily and
waited...and
waited....and waited some more, but no fry made an appearance. Meanwhile
an adjacent
and identically set up pond that had been stocked with a trio of the
beautiful
black-speckled form of F. chrysotus was producing large quantities of
young fish. I was
totally at a loss to explain the difference. Since I always spend a
considerable time in late
spring and summer participating in rare plant surveys in Utah, and
leading tropical fish
study and collecting trip to the Amazon River, I did not have time to
analyze the
situation.
By September the adult cingulatus were still actively courting, but
there were still no fry
to be seen. I reasoned that even if this species was an efficient egg or
fry eater that a few
young would survive. The vegetation was certainly thick enough to
provide adequate
hiding places. I then contacted Ray Wolff, a very talented breeder of
native fishes, who
had also received some of these fish from Robert.. He had also placed
them in an outside
pond, and had experienced the same frustrating lack of fry.
With this species’ natural breeding season coming to an end, I emptied
the pond and
brought all the fish inside. My luck did not improve. One male quickly
killed the other,
and then committed suicide by somehow jamming himself headfirst into a
sponge filter’s
lift tube! Ray wasn’t doing any better and was down to only one female
and three males.
When I told him about my situation he immediately sent two of his males
to me. It was
now about Oct 1, and only one of my females seemed to still be heavy
with eggs. I placed
her in a 20 gallon “long” aquarium with the more robust of Ray’s males.
The only
furnishings were a sponge filter and two large bottom spawning mops and
two equally
large floating mops. As an experiment, one of the floating and bottom
mops were made
of dark brown Dacron yarn, the others of white. the water was medium
hard (150ppm)
and with a pH of 6.8.
The breeders were fed in the morning with flake food and in the evening
with live
mosquito larvae. At first the male was a bit overly zealous in his
courtship, keeping the
female hidden much of the time among the strands of the mops. This
aggressiveness
subsided after less than a week and eggs could be seen in the bottom
mops. This
answered one of my questions: this species does not seek out its eggs
for food. Every four
or five days the mops were removed from the aquarium and checked for
eggs.
Apparently, unlike the golden ear and starhead killies, this species is
a confirmed bottom
spawner (like F. zebrinus). Eggs were only found in the bottom mops, and
virtually all
were laid in the dark brown mops. After being picked from the mops, the
rather large
eggs (almost 2mm) were removed to a separate container for incubation.
This container
was a clear plastic shirt box with about one inch of water taken from
the breeding
aquarium.. No aeration was used, but as a precaution against the eggs
fungusing a bit of
methyline blue was added to the water. At 74 F the eggs began to hatch
after 10 - 12 days
incubation. The newly hatched fry are very large, and have no trouble
consuming newly
hatched brine shrimp nauplii. This was their sole food for about 10
days, It was then
alternated with powder-fine dry food. I now have over 50 healthy
cingulatus fry. They are
growing very rapidly, and at the time of writing (Dec. 19) the oldest
are now a little over
1/2 inch long.
By the end of November the female’s egg production had ceased but the
male still was
still courting. In order to prevent any damage to the female the pair
was removed from
the breeding tank and placed in a 110 gallon, heavily planed native fish
community tank
that also housed the other trio. In these larger quarters it was easier
for the females to
keep away from the male. Except for the larger male occasionally chasing
the smaller
one, all has been peaceful, with no other infra- or interspecific
aggression shown by this
species. Among the many other fish in this aquarium are two pairs of
golden-ear killies. I
find it interesting that these two related and somewhat similar
killifish have been
mutually compatible.
In summary, I still do not know why F. cingulatus proved non-productive
in an outdoor
pond, but it is a beautiful and easily accommodated species that appears
to be quite easily
spawned and raised in an aquarium. A word of advise: courting males can
be a bit rough
on the female (in my experience not as bad as F. trysts). I therefore
recommend using at
least a 10 gallon tank for breeding them and provide plenty of mops to
provide hiding
places as well as safe retreats for the female. My experiences also
indicate that only one
male should be used. If you are lucky enough to have more than one pair
of this fish I
recommend switching out males and females periodically as a means of
assuring as much
genetic diversity in the fry as possible. By the way, in speaking with
Ray Wolff I have
learned that after he brought his adult fish inside, he also started
collecting eggs from
them.
I would be interested in hearing from other members who have had
experience with the
banded topminnow.