Altolamprologus calvus "Black Congo"

Black CongoBLAK COHN-goh (approx.)

The fish

How this cichlid is built, and everything about how it lives, eats and breeds, is shared with the species — this page doesn't repeat it.

Read the full Altolamprologus calvus account →

Specific to Black Congo

  • Collection locality & coordinates
  • Local coloration — best judged from the living-fish photo
  • Kept as a single-provenance line, never crossed with other collection points

Care facts below are the species' — shared with Altolamprologus calvus.

IUCNNEAR THREATENED · 2025
CARESNOT LISTED
Scientific size5.5 in13.5 cm total length
Temperature73–81 °F23–27 °C
pH8–9alkaline
Hardness (GH)very hardup to 339 ppm
Depth10–134 ft3–41 m
DietCrevice micro-predator (shrimp, small crustaceans, small fish fry)
BreedingSubstrate / crevice spawner (not a mouthbrooder)~200–300 eggs
Sexual dimorphismYesMales markedly larger with longer trailing fins and a scaleless forehead; females smaller and rounder-bodied
PhotographsSee photosGoogle Images →

The Black Congo population

The "Black Congo" is a locality form of Altolamprologus calvus collected along the western, DRC-side shore of Lake Tanganyika, and it is the darkest calvus in the hobby — a near-black body flecked with brilliant white to cream scale spots. Zambian populations show softer contrast, grey or charcoal against pale speckling, but the Black Congo's ground colour approaches true black, giving it a graphic, high-contrast look that keeps it in demand among Tanganyikan keepers. The name is informal and carries no taxonomic weight; it is simply hobby shorthand for calvus sourced from the DRC coast rather than from Zambia or Tanzania. It has held its place in the specialist trade for decades because DRC-origin stock reliably reproduces the dark phenotype, which breeders read as a real population difference rather than chance variation.

Colour reference: living Black Congo fish at seriouslyfish.com

About the species

Altolamprologus calvus — the pearly or black calvus — is a slender, armor-scaled predatory cichlid found only along the rocky southwestern shore of Lake Tanganyika. Its body is so strongly flattened from side to side that it can slip into rock cracks too narrow for almost any rival or predator — a build that doubles as a hunting tool and as the basis of an unusual breeding trick, in which the female spawns inside a crevice too small for the male to follow. Patient, deliberate, and slow-growing, it ranks among the lake's most coveted aquarium fish, and its fortunes are now tied to the silting of the very shoreline it depends on.

Full Altolamprologus calvus account →

Sources

  1. Poll, M. (1978). Contribution à la faune ichthyologique du lac Tanganika. Bulletin de l'Académie Royale de Belgique 64: 725–758
  2. Eschmeyer's Catalog of Fishes — Altolamprologus calvus
  3. FishBase — Altolamprologus calvus
  4. Konings, A. (2015). Tanganyika Cichlids in their Natural Habitat, 3rd ed. Cichlid Press
  5. IUCN Red List — Altolamprologus calvus (Near Threatened, 2025)
  6. Seriously Fish — Altolamprologus calvus
  7. Cichlid Room Companion — Altolamprologus calvus
  8. cichlid-forum.com — Altolamprologus keeping and breeding