A very popular aquarium is one devoted
to keeping the larger African cichlids, primarily
from Lakes Malawi and Tanganyika in the East African
Rift Valley. These fish require hard and alkaline
water – pH around 8.0 and as hard as you can
make it, which happens to be the water that comes
out of many taps in hobbyists’ homes. These
fish are often referred to as “mbuna”,
which is the local word meaning “rock-dwellers”,
which tells you a lot about how to set up a tank for
these fish.
Since “mbunas” are fairly large fish
– the adults are 4” to 5” or so
– they do best in larger tanks, say 30 gallons
and up. Many different fish can be kept together in
a tank, as long as you either a) give them enough
rocks for cover so that each fish can establish a
territory, or b) you keep enough fish in the tank
that no one fish can establish a territory. In large
tanks with rock piles these fish will often spawn
– most of them are maternal mouthbrooders –
and one day you will see baby fish darting in and
out of the rocks.
Many of these fish are what are called “harem
breeders”, in which case a single male will
be the boss of a small group of fish, which include
females and often a few sub-dominant males. Many hobbyists
find it interesting to keep a tank devoted to a single
species in a harem like this. Other of these larger
African cichlids have different spawning habits, and
prefer other types of habitats such as fine sand and
rock crevices.
The “mbunas” have provided one of the
most interesting studies of evolution and speciation,
since the different species in the lakes have evolved
over a relatively short period of time (a couple hundred
thousand years or so), and are specialized in terms
of the type of habitat they live in, and the foods
they eat; they are broken into “guilds”
according to how they feed. A potential problem to
try and avoid is the fact that the differences between
species of these fishes are often not that great that
they will not interbreed – if one of their own
species is not available, a cousin will do. If closely
related species are kept together this will often
result in hybrids, which are never as attractive as
the individual species, and which are of no value
in the hobby.
African cichlids are probably kept by more hobbyists
than any other group of fishes, a fact that attests
to their beauty, hardiness and interesting spawning
behavior. Of all the groups of fishes kept in the
hobby, the African “mbuna” cichlids are
probably the easiest to keep.
Brackish Water Fish
There are a number of fish that require water with
salt in it, ranging anywhere from a few tablespoons
per gallon up to almost full strength seawater. These
fish should not be kept in a regular community tank.
As they a) will not do well without the large amount
of salt in the water and b) they are in general somewhat
rough customers, who do best with other brackish water
fishes.
Some of the brackish water fish that we may carry
at times include:
*Scats and monos – these fish are fast-moving
schooling fish who do best in large groups in large
tanks
*Puffers – these fish vary in size from 2”
cuties to 18” bruisers, and they also do not
all require brackish water.
* Gobies – These guys are very popular, the
best ones being the “bumblebee” goby,
which is only a little over an inch long and looks
like a bumblebee – yellow and black.
*Mollies – although adapted to complete fresh
water, most of the larger mollies do well in brackish
water tanks, or even straight seawater.
*Mudskippers – very interesting fish, these
guys really need a tank to themselves. They come from
mangrove flats, and spend more time out of the water
perching on a branch or rock than in the water.
*Archerfish – another interesting fish that
really need a tank for them alone. They “shoot”
water at insects above the water, and make very interesting
single pet fish.
Brackish water fish are interesting, and can be kept
individually for some species, or as a community of
brackish water fishes for others. The only real drawback
is that it is impossible to keep live plants in a
brackish water tank, so you need to do regular water
changes to keep nitrates low. Making a water change
you need to add the correct amount of salt for the
amount of water being changed – adding fresh
water to make up for evaporation you do not add salt,
since the salt stays in the water when the water evaporates.
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