Calvus cichlid

Geographic Origin and Habitat: Altolamprologus calvus is a freshwater cichlid endemic to Lake Tanganyika and reported from its southwestern part. FishBase classifies it as benthopelagic and associates it with rocky habitat, narrow cracks and shallow caves. Those documented use-sites make the arrangement of the lower rocky zone relevant to behaviour and refuge. They do not show that every depth, shoreline or local microhabitat in the lake is interchangeable for this species.

Taxonomy and Morphology: The accepted name is Altolamprologus calvus (Poll, 1978), with Lamprologus calvus Poll, 1978 as the basionym. The taxonomic sources place it in Cichlidae, subfamily Pseudocrenilabrinae and tribe Lamprologini; the stored subfamily is Pseudocrenilabrinae, not the tribe. Its deeply laterally compressed body is linked to entry into narrow cracks and shallow caves. FishBase reports a maximum of 13.5 cm total length for male or unsexed fish.

Social Behaviour: The direct species account describes A. calvus as a stalker cruising rocky habitat 30–100 cm from the substrate. This supports close-to-rock foraging and shelter use, not a claim that it is motionless or nocturnal. Territory, crevice access, feeding and individual behaviour can change interactions. A shared lake origin does not demonstrate social compatibility, and small animals can be relevant to predation risk when the documented crustacean diet is considered.

Colouration and Sexual Dimorphism: The reviewed material supports the compressed body and the reported total-length maximum, but not one universal colour morph, a fixed male-to-female size ratio, or a diagnostic fin difference. Trade names and photographs can reflect local or selected appearances rather than a taxon-wide rule. Do not infer sex, age, health or provenance from colour alone. Where management depends on sex, use an appropriate method and keep the identification limit separate from visible appearance.

Aquarium Setup: Build around stable rockwork with narrow cracks and shallow caves, the documented use-sites for this species. Keep refuges accessible, avoid unstable stacks and detritus traps, and retain enough open access to observe feeding and conflict. The evidence describes a rocky benthopelagic cichlid, not a generic open-water fish. It does not establish one universal tank volume, lighting level or substrate; those choices need assessment of the actual system and animals.

Diet and Feeding: FishBase reports a diet mainly of shrimps and other crustaceans. Use that evidence to select suitable animal-prey foods and observe whether each fish obtains them in a mixed aquarium. The account does not establish a fixed portion, texture or feeding frequency, and does not make fish fry the principal documented prey. Adjust feeding from intake, body condition, competition and uneaten food, especially where the rocky layout can retain debris.

Water Quality: FishBase reports freshwater reference values of 23–25 °C, pH 8.0–9.0 and dH 9–19. Treat this as a source-bound envelope, not a rapid-acclimation recipe, treatment, or proof that a single hardness product is required. Keep conditions stable and interpret measured values with the whole system. The consulted account does not validate universal KH, TDS, conductivity, nitrate or water-change targets for every aquarium or population.

Compatibility and Cohabitation: Evaluate tankmates in the real layout rather than from a fixed list of Lake Tanganyika species. Body size, shared crevice use, feeding access, refuge and individual territorial behaviour all matter for a rocky stalker that takes crustaceans. Do not assume that a smaller animal is safe or that another cichlid from the lake is automatically compatible. Separate or revise the arrangement when conflict, injury or suppressed feeding shows the setup is failing.

Aquarium Breeding: FishBase reports a female guarding approximately 200 eggs. That observation supports careful protection of a secure reproductive site, but not a shell-only method, fixed pair or harem, sexing shortcut, or guaranteed hatch and survival outcome. Breeding management should respond to observed compatibility, space, refuge and water conditions. Minimise disturbance and do not force a social arrangement from a general profile or a trade description.

Risks and Disease: No taxon-specific disease cause or treatment protocol was confirmed in the consulted sources. Do not use this card to diagnose a lesion, refusal to feed, respiratory sign or loss, or to medicate every fish. Start from observed signs, measured water conditions, diet and husbandry context; obtain qualified aquatic-animal assessment when signs persist, spread or cause losses. Prevention, control and any treatment must fit the diagnosed problem, host, system and product or veterinary direction.