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. Others 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 – Also 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.