Aquarist Atlas
↑ Collection form of Petrochromis macrognathus

Petrochromis macrognathus "Lyamembe"

Lyamembe — lyah-MEHM-beh (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 Petrochromis macrognathus account →

Specific to Lyamembe

  • 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 Petrochromis macrognathus.

IUCNLEAST CONCERN · 2025
CARESNOT LISTED
Scientific size7.9 in20 cm total length
Temperature73–82 °F23–28 °C
pH7.8–9alkaline
Depth0–10 ft0–3 m
DietAufwuchs grazer; scrapes algal biofilm, diatoms, and associated microfauna from sunlit rock surfaces.
Breedingmaternal mouthbrooder~15 eggs or more
Sexual dimorphismYesMales are larger with bolder territorial behavior; egg-spot ocelli on the anal fin are present in males and absent in females.
PhotographsSee photosGoogle Images →

The Lyamembe population

Petrochromis macrognathus "Lyamembe" is the Lyamembe population of Petrochromis macrognathus, a geographic colour form from the Tanzania coast of Lake Tanganyika in the north-central part of the lake. It is the same species as Petrochromis macrognathus, distinguished by its collection locality and local coloration; aquarists keep and breed it as a discrete, provenance-labelled line.

Colour reference: living Lyamembe fish at tanganyika.si →

About the species

Petrochromis macrognathus is a rock-grazing cichlid found only in Lake Tanganyika, where it scrapes a living off the algae-covered boulders of the shallow, wave-battered shoreline. Its name means "large jaw," and that jaw — a strongly projecting upper jaw and pronounced downturned mouth, most extreme in this species though also present in its close relative P. trewavasae — lets it shave large patches of algal film off vertical rock at a low angle. It is one of the most specialized and, in captivity, one of the most belligerent members of an already pugnacious genus.

Full Petrochromis macrognathus account →

Sources

  1. tanganyika.si — Petrochromis macrognathus "Lyamembe"
  2. FishBase — Petrochromis macrognathus (summary)
  3. Catalog of Fishes (Eschmeyer) — Petrochromis macrognathus
  4. GBIF — Petrochromis macrognathus Yamaoka, 1983
  5. Encyclopedia of Life — Petrochromis macrognathus
  6. Yamaoka, K. (1983). A revision of the cichlid fish genus Petrochromis from Lake Tanganyika, with description of a new species. Jap. J. Ichthyol. 30:129–141 (record via GBIF)