Cyprichromis Leptosoma (Blue Flash)

Cyprichromis leptosoma, the Slender Cichlid or Sardine Cichlid, is a fascinating and distinctive cichlid native to Lake Tanganyika in East Africa. Unlike most cichlids that hold territories and pair bond, Cyprichromis is a pelagic, open-water schooling cichlid that forms large shoals in the open water column above rocky substrates in the lake's littoral and sub-littoral zones.

Males in the 'Blue Flash' variant display extraordinary electric blue-violet iridescence across the body and head with vivid yellow dorsal and caudal fins — a colour combination that is particularly striking when seen in large groups. Multiple colour morphs exist across the lake, with some localities showing yellow or blue males and others showing different colour combinations entirely.

Females are smaller and significantly less colourful — primarily silver-grey. Like all Tanganyikan cichlids, Cyprichromis is a mouthbrooder: females incubate eggs in the buccal cavity and hold fry for an extended period. Remarkably, Cyprichromis performs vent-spawning — the female releases eggs into the water column before catching them in her mouth, rather than laying them on a surface first.

Keeping Cyprichromis requires a tall aquarium with good vertical space (they are mid and upper-water fish, not substrate dwellers), alkaline, hard water matching Tanganyikan chemistry, and groups large enough (10+) to allow natural schooling behaviour. They are best kept as a single-species colony or in a carefully designed Tanganyikan community.

Tank Setup: A minimum 200-litre tall aquarium (60 cm height or more). Provide open mid-water and upper water swimming space with some rocks at the base for other Tanganyikan species. Strong filtration and good water movement with surface agitation for oxygenation. Crushed coral or aragonite substrate to maintain alkaline pH.

Water Parameters: Temperature 24–27°C; pH 7.8–9.0; GH 12–20 °dH; KH 10–18 °dH. Hard, alkaline water matching Tanganyikan chemistry is essential. Do not use soft water or acidifying additives.

Feeding: Omnivore/plankton feeder in the wild. Feed high-quality floating or slow-sinking flake, micro pellets, frozen Daphnia, brine shrimp, and Mysis shrimp. Feed two to three times daily in small amounts to keep the food in the water column where they feed.

Tank Mates: Best with other Tanganyikan species from different ecological niches: Altolamprologus (cave dwellers), Neolamprologus shell dwellers, Julidochromis. Avoid mixing with Malawi Mbuna or other non-Tanganyikan cichlids.

Behaviour: Open-water schooling cichlid — unique among cichlids. Groups of 12+ school attractively in the upper water. Mouthbrooding females separate from the group briefly during brooding. Males display vivid colours constantly when competing.

Health: Hardy when Tanganyikan parameters are maintained. Sensitive to soft or acidic water. Weekly 25–30% water changes with matched chemistry are essential.