Congo Killies - PageSuite

importance. Inland species, in particular those from
higher regions, prefer temperatures of around 68–70°F
(20–21°C), sometimes even lower. The average domestic
aquarium cannot provide this, so you should think
carefully before acquiring such species. However, these
cool-water species are rarely found in the aquarium
trade. Examples of species that require cooler maintenance
include Aphyosemion mimbon, A. coeleste, and A.
maculatum.
On the other hand, coastal species or species from
the lowlands and savanna regions live at temperatures
similar to those in our aquariums. The water parameters
there generally resemble those of average tap water, so
such species are better suited to the normal aquarium
than species from the interior. Suitable species include
Aphyosemion australe, A. striatum, A. primigenium, and A.
marginatum, for example.
Everything but greens
Diet has a significant influence on these fishes. Essentially,
green food is of no interest to Aphyosemion. They
will take any live foods that they can overpower, from all
sorts of mosquito and midge larvae, water fleas, Cyclops,
and fruit flies to Tubifex and White or Grindal Worms.
Aphyosemion will also reliably take Artemia nauplii as long
as the latter remain alive, but they aren’t adequate food
for larger fishes in the long term. With good feeding the
females will visibly fill with eggs. If this doesn’t happen
for an extended period, other foods should be offered.
In my personal experience, Aphyosemion much prefer
live food, and fishes that are accustomed to it are reluctant
to take frozen or dry food. This can cause problems
in times of live-food shortage. Naturally that doesn’t
happen with frozen or dry food, as these are always
available.
and hence no obvious territories are established. Where
several fishes live together in an aquarium there is a high
probability that there will be a “top dog” who chases
the other males and pursues the females. The almost
constant harassment of females by males is part of
normal behavior. Healthy individuals can cope with that,
and there should be no losses as long as there are places
to which subordinate males and oppressed females can
retire. Only extremely weak specimens will be unable to
cope in the long term.
Danger of hybridization
Generally speaking, Aphyosemion species can be kept with
other fish species; as a rule they do not occur alone in
the wild. However, tankmates should never look similar
to their predators, which include larger characins and
cichlids. And they don’t need to be actually dangerous for
Aphyosemion. It is enough if their appearance causes the
Aphyosemion anxiety. On the other hand, small tetras and
small barbs are fine. In addition, fish species from other
regions can generally be kept with Aphyosemion, as long
as they don’t actually hunt them.
If you really want to obtain the maximum benefit
from these fishes in the aquarium, it is advisable to buy
not just a trio, but a larger number, all at the same time.
That can mean four pairs or more. The fishes will then
exhibit more natural behavior and will be constantly visible
and less retiring.
It is also possible to keep several Aphyosemion species
together in the aquarium, but only if you have no ambition
to breed them. Because many of the females look
very similar and related species will generally cross, you
should at least ensure that the species chosen are as different
from one another as possible. But any fry that may
turn up should never leave your home.
Not territorial
Aphyosemion are not considered aggressive towards other
fishes. However, within the genus and, naturally, within
their own species, there are sometimes very violent
squabbles. Noticeably weaker individuals can suffer badly
as a result. And females will vigorously harass males that
are very small. It is not usually possible to predict if this
will happen. Note that in some individual species, for
example Aphyosemion amoenum, it is not unusual for
females to grow more rapidly and become significantly
larger and stronger than males.
Some individuals are very timid. This isn’t necessarily
due to an error in maintenance; even in the wild it is
undoubtedly advantageous to the survival of the species
for there to be cautious as well as outgoing specimens. In
times when food is in short supply, the outgoing individuals
are at an advantage, but in the event of major
predation pressure it is the retiring specimens that will
survive.
Aphyosemion are not territorial in the normal sense,
Not too much light, not too much space
The subject of minimum aquarium size conceals numerous
pitfalls, especially when it comes to the killifish
hobby. Be that as it may, the usual 2-foot (60-cm)
beginner’s aquarium of 15–20 gallons is suitable for up
to four pairs of adult Aphyosemion. And you can usually
keep even more in it. Problems arise only when a single
dominant individual terrorizes the other fishes. In such
cases, even a larger aquarium doesn’t guarantee a solution.
The dominant individual chases the others all over
the aquarium and the weak specimens can’t keep out of
sight of the alpha individual for long. In my experience
Aphyosemion are often rather shy and retiring in larger
aquariums. Only if there are sufficient fishes of a species
present will they be lively and outgoing in large aquariums
as well.
Aphyosemion have only a limited acquaintance
with lush aquatic plants in their native waters—usually
streams that, depending on the time of year and the
amount of precipitation, are a few meters wide and a few
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