Congo Killies - PageSuite

COVER
STORY
The keeping of
Aphyosemion
in the aquarium
by Olaf Deters It is hard to imagine how a fish can be attractive, colorful, not too
large, peaceful, and interesting, and still not be common in the aquarium hobby, but this
has been true of killifishes for years. In hopes of awakening more interest in them, I will
spell out just what the aquarist needs to know to keep Aphyosemion species successfully.
TOP: H. NIGL; MIDDLE & BOTTOM: O. DETERS
Opposite page,
top: The “Cape
Lopez,” here the
golden form of
Aphyosemion
australe, is the
best-known
member of the
genus.
Middle:
Aphyosemion
castaneum
is very
attractive, but
unfortunately
also very
demanding.
Bottom:
Aphyosemion
striatum is
also found
in the trade
now and then.
The species
tolerates higher
temperatures.
The killifishes have been known to generations
of aquarium keepers, and there are numerous
species; they deserve greater recognition on account
of their colors, but only a few standard
species are found in the aquarium trade—for
example, Aphyosemion australe, known as the
“Cape Lopez” killie. Interestingly, Aphyosemion
australe is not considered the easiest species in
the genus to maintain.
One reason for the poor spread of Aphyosemion
species in the aquarium hobby may be
certain long-standing prejudices against them,
which cannot be entirely discounted. Nevertheless,
the species are not really complicated—
many “standard fishes” are more demanding.
The aquarist needs only to make a few adjustments
in order to keep Aphyosemion, and they
will generally prove to be rewarding pets.
Accomplished jumpers
There is the matter of jumping, for example.
Yes, Aphyosemion can and will jump out of the
aquarium if given the opportunity. In the wild
they are not at the top of the food chain, so
they try to evade their predators by escaping
into areas where the water is shallow, sometimes
only a few centimeters deep. Should
danger also threaten there, the best escape
method is to leap up, quickly and as far as
possible.
However, this behavior isn’t equally
expressed in all species. Some exhibit jumping
behavior in an extreme form, others not
at all. But for safety’s sake, the aquarium for
Aphyosemion should be tightly covered. These
fishes will find the smallest gap in the cover
glass, for example where filter parts enter or
exit. Any gaps can be plugged with filter wool.
If you don’t take these precautions, things may
be fine for a while, but one day you will find a
desiccated mummy on the floor or a fish will
have disappeared without trace.
It is also believed that killifishes aren’t
long-lived. They certainly don’t live to be
ancient, but it is usually possible to keep them
for two or three years, and sometimes longer,
though you shouldn’t raise your expectations
too high. Aphyosemion will seek to breed if
given the opportunity, but the presence of a
mate causes continual stress, which inevitably
shortens the lives of the fishes. It is questionable
whether the alternative of keeping them
singly to prolong life expectancy is really wise.
Moreover, in the long term, over-warm water
can reduce life expectancy.
Water and temperature
It is sometimes stated that Aphyosemion are demanding
when it comes to the water, and that
idea didn’t appear out of thin air. These fishes
come mainly from flowing waters and won’t
tolerate old and polluted water for long. They
may survive for a while in such conditions,
but they will age more rapidly. So regular water
changes are very beneficial for them. On the
other hand, special preparation of the water is
only necessary if it is very hard. The majority of
Aphyosemion species can readily be maintained
and even bred in medium-hard tap water.
The correct water temperature is of some
AMAZONAS
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