Care
Nimbochromis polystigma has a widespread distribution throughout Lake Malawi. Here, this piscivorous species is found in many different habitats but is most common in vegetated areas with beds of Potamogeton and Vallisneria, and sometimes at the rock-sand interface. The aquarium should be at least 6ft long and aquascaped with open expanses of sand in addition to a few rocky areas and some thickets of Vallisneria. Décor such as ocean rock can be used to build sturdy structures which stretch from the base of the tank to near the surface of the water. These structures should be built with the purpose of creating many crevices for the fish to explore but constructed in such a way so as to keep the rocks stable if the fish start to dig around and underneath them. Although a substrate of coral sand or Aragonite is often recommended to help to keep the water hard and alkaline, these fish feel safer and show better colours over a darker substrate. The Aragonite or coral sand can always be placed into a mesh bag and kept inside the external filter for buffering purposes. N. polystigma is solitary in nature and can be kept singly in the aquarium, or one male with a harem of several females. Tankmates must be chosen with care as smaller fish will be eaten. Suitable companions could include other large rift lake species such as Dimidiochromis compressiceps, Fossorochromis rostratus, other sizeable Haplochromis/Nimbochromis species, large Synodontis catfish etc. In the wild, this fish plays dead on the substrate in order to capture and eat small unwary Mbuna. It will lie on its side until the smaller fish come close to inspect the 'carcass', only for it to suddenly awaken and snatch up its prey with lightning quick reflexes. It is this distinctive hunting method that has earned the fish the local name of Kalingono, which means 'sleeper'. May also be seen on sale as Hyena Cichlid.
Feeding
Offer a variety of meaty frozen foods. Smaller specimens will take mosquito larvae, vitamin-enriched brineshrimp, and Mysis shrimp, whilst larger fish will take krill, prawns, lancefish, whitebait etc. A good quality flake and appropriately sized cichlid pellets should also be provided.
Breeding
Maternal mouthbrooder. When ready to spawn, the colouration of the male will intensify. He will choose and clean a spawning site, either a flat rock or a small depression dug in the substrate, then display to the female fish until one accepts him. The female will lay a line of eggs before moving away and allowing the male to fertilise them, before taking them into her mouth. This is repeated until the female is spent. The eggs may be incubated for around 25 days until they hatch into free-swimming fry. The young are large enough to take baby brineshrimp (Artemia nauplii) as soon as they are released.
