The cichlids are one of the most popular families of aquarium fish. This is despite the fact that many hobbyists think of them as aggressive and intolerant of their tankmates and get special delight in destroying aquarium plants. This, however, does not apply to all of the cichlids as most of unpleasant experiences people have had with cichlids are the result of poor selection of species and improper care. Most cichlid species hail from Africa, with the vast majority of these inhabiting Lakes Malawi, Tanganyika and Victoria, and the Great Rift Valley. About 100 species come from Mexico, Central America and the Caribbean Islands, and about 250 species come from South America.
With an estimated 1,000-plus species the family Cichlidae is one of the largest families of fish known. They are all freshwater fish. Some of the most easily seen characteristics are a single long dorsal fin comprised of both a spiny and soft portion and anal fin with three or more spines; a lateral line that is divided into two separate sections and a single, rather than paired, nostril opening on each side.
There is so much diversity of size and shape among the different species of cichlids that it is hard to believe they all belong to one family. There are giants that measure from 28 to 32 inches (70-80 cm) in length, and dwarfs that are full grown at 1.5 inches (3.4 cm). The vast majority of cichlids are of suitable size for the average home aquarium, beautifully colored and exhibiting fascinating and complex courtship and breeding behaviors. Most make hardy, long-lived and easily satisfied aquarium inhabitants.3
Most of the African Cichlids are aggressive and territorial, even more so than their Central and South American cousins. One way to defuse future battles is creating ample hiding places in the form of rockwork and driftwood when you are setting up your African cichlid tank. The dominant fish will stake out its territory, usually in the center of the tank, and the others will have smaller territories within the labyrinth of rocks and wood.
Another way to dilute aggressive behavior is by "controlled crowding," where you put about twice as many fish in the tank as you would normally. If you are going to try this technique, make sure you have ample hiding places, a great filter, and don't overfeed.2
The term "mbuna" comes from the Chitumbuka language spoken in northern Malawi. The term has no formal taxonomic validity, and the mbuna species group is not clear-cut, which means that they have no characters or behavioral traits that are not shared with other groups of cichlids. While mbuna populations are largely restricted to the rocky shore habitats, many species of mbuna are also found away from rocky habitats.
All mbunas are maternal mouthbrooders. They have elaborate courtship rituals. Males attract females by darting in front of them; then they attempt to lead the female, using "waggling" movements in the direction of the male's preferred spawning site. Spawning sites vary between species: most species prefer to spawn in a secluded cave under rocks; others prefer to spawn in the open, often on the side of a steeply-sloping rock. Eggs are laid singly or in small numbers and then rapidly collected in the mouth of the female. Clutches vary in size, but rarely number more than 50. After spawning, males play no role in parental care. Brooding females generally hide away under rocks, often in groups, and do not seem to move much. Eggs and larvae are brooded for 20-30 days before free-swimming juveniles are released. Unlike other cichlid species, mbuna females do not stand guard over free-feeding juveniles or allow the young fish to return to their mother's mouth when threatened by predators.4
Males of most mbuna species are territorial. Most species of mbuna eat algae, plankton, invertebrates or fish fry.
It is considered that mbuna comprises about half or more of cichlid species. Primary threats to the cichlids of Lake Malawi are overfishing and pollution.