Pearly compressiceps (Black calvus)

The black calvus is a slow, deliberate predatory cichlid endemic to the southern rocky shores of Lake Tanganyika. Its laterally compressed, scute-armoured body lets it slip into crevices to ambush shrimp and fry. Reaching about 13 cm, it is peaceful for its size toward unrelated fish but territorial with its own kind, so keep a single specimen or a bonded pair with plenty of piled rockwork, caves and empty shells. It requires the lake's hard, alkaline water: pH 7.8-9.0, high carbonate hardness, 24-27C, and pristine, well-filtered conditions. Feed a carnivorous diet of frozen mysis, brine shrimp and quality pellets; avoid protein-rich mammalian foods that cause bloat. Slow-growing and long-lived, it is a shell-brooding species that deposits eggs in narrow cavities. An excellent centerpiece for Tanganyikan setups.