Aquarist Atlas
↑ Collection form of Tyrannochromis macrostoma

Tyrannochromis macrostoma "Chiwi Rocks"

Chiwi Rocks — CHEE-wee ROKS (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 Tyrannochromis macrostoma account →

Specific to Chiwi Rocks

  • 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 Tyrannochromis macrostoma.

IUCNLEAST CONCERN · 2019
CARESNOT LISTED
Scientific size11.8 in30 cm standard length
Temperature75–82 °F24–28 °C
pH7.7–8.8alkaline
Depth16–98 ft5–30 m
DietPiscivore (hunts mbuna & other small fish)
BreedingMaternal mouthbrooderup to ~150 eggs
Sexual dimorphismYesMales much larger (~35 cm vs ~24 cm) and, when breeding, brilliant light blue with a pale-yellow belly and a near-black lower body; females and juveniles yellowish grey-silver with a dark mid-lateral stripe.
PhotographsSee photosGoogle Images →

The Chiwi Rocks population

Tyrannochromis macrostoma "Chiwi Rocks" is the Chiwi Rocks population of Tyrannochromis macrostoma, a geographic colour form from the Malawi coast of Lake Malawi in the central part of the lake. It is the same species as Tyrannochromis macrostoma, distinguished by its collection locality and local coloration; aquarists keep and breed it as a discrete, provenance-labelled line.

Colour reference: living Chiwi Rocks fish at malawi.si →

About the species

Tyrannochromis macrostoma is a big-jawed, fish-eating cichlid endemic to Lake Malawi, where it patrols the sediment-dusted rocky shore hunting mbuna with a sudden sideways lunge. Its most arresting trait is reversed countershading: the belly darkens to near-black during a hunt, the opposite of almost every other fish, a camouflage trick tied to the head-down, tilted angle from which it strikes. Despite a fearsome mouth, it is a comparatively calm predator outside the breeding season, and the IUCN lists it as Least Concern across its lake-wide range.

Full Tyrannochromis macrostoma account →

Sources

  1. malawi.si — Tyrannochromis macrostoma "Chiwi Rocks"
  2. Eschmeyer's Catalog of Fishes: Tyrannochromis macrostoma (Regan 1922)
  3. Eschmeyer's Catalog of Fishes: Haplochromis polyodon (synonym of T. macrostoma)
  4. FishBase: Tyrannochromis macrostoma
  5. GBIF: Tyrannochromis macrostoma occurrence and taxonomy
  6. Chavula et al. (2023), Lake Malawi/Niassa/Nyasa basin: Status, challenges, and research needs, J. Great Lakes Research 49(6):102241