African cichlids have a reputation among aquarists as being aggressive brutes, capable of terrorizing and murdering all who stand in their way. But really this description is most applicable to a few genera of rock-dwelling fishes known as the mbuna. Life among the shoreline boulders is tough and highly competitive, especially for those species which make a living grazing upon the algae and microorganisms growing atop the substrate. On the other hand, the closely related genera Mchenga and Copadichromis constitute a distinct lineage of peaceful planktivores known as the utaka.
Large shoals of Copadichromis form above the rocky shorelines and out above the open sand flats throughout Lake Malawi. The group is characterized by a large tubelike elongation to the mouthparts, visible when they are fully extended during feeding. This allows these fishes to quickly vacuum up aquatic insects and crustaceans. There are even a couple specialized species (C. pleurostigma, C. trimaculatus) which have taken to feeding heavily on phytoplankton.
For those aquarists whose favorite color is blue, Copadichromis azureus certainly lives up to its scientific name. Mature males are a rich, lustrous blue all across the body, while females and juveniles are typical of the genus, being drab and with dark spots along the midline. Note that it is quite common to see this fish misidentified in older aquarium literature as Haplochromis chrysonotus (which shouldn’t be confused with the true Copadichromis chrysonotus, an unrelated fish entirely).
Utaka show a diverse array of breeding strategies. Those associated with sandy environments, such as C. azureus, generally establish their breeding territories in self-constructed bowers built beneath beneath nearby rocks. The mouth-brooding females of this Copadichromis lineage congregate near the bottom, while in the boulder-associated C. borleyi and its ilk the females swim high off the bottom. Others (e.g. C. chrysonotus) spawn in the water column.
As with all utaka, this species is undemanding in an aquarium, feeding readily on nearly any foods offered. Groups can be safely kept together and would make for a stunning species-only display, though most opt to keep single specimens or breeding pairs. Avoid mixing with overly aggressive mbuna species, though many other Malawian and Tanganyikan genera make for suitable tankmates, such as the Aulonocara peacock cichlids or docile groups like Cyrtocara, Protomelas, Placidochromis, Otopharynx and Sciaenochromis.