Aquarist Atlas
↑ Collection form of Xenotilapia rotundiventralis

Xenotilapia rotundiventralis "Cape Nangu"

Cape Nangu — KAYP NAHN-goo (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 Xenotilapia rotundiventralis account →

Specific to Cape Nangu

  • 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 Xenotilapia rotundiventralis.

IUCNLEAST CONCERN · 2025
CARESNOT LISTED
Scientific size2.1 in5.3 cm standard length
Temperature75–82 °F24–28 °C
pH8.6–9.3alkaline
Depth30–36 ft9–11 m
DietSpecialist zooplanktivore; picks individual zooplankton from open water with a small protractible mouth.
BreedingBiparental mouthbrooder (maternal first, then partial brood transfer to male)Small, on the order of a few dozen young
Sexual dimorphismYesNo reliable external dimorphism in color, size, or shape; sexes are distinguished only by the genital papilla, with males averaging marginally larger SL than females.
PhotographsSee photosGoogle Images →

The Cape Nangu population

Xenotilapia rotundiventralis "Cape Nangu" is the Cape Nangu population of Xenotilapia rotundiventralis, a geographic colour form from the Zambia coast of Lake Tanganyika in the southern part of the lake. It is the same species as Xenotilapia rotundiventralis, distinguished by its collection locality and local coloration; aquarists keep and breed it as a discrete, provenance-labelled line.

Colour reference: living Cape Nangu fish at tanganyika.si →

About the species

Xenotilapia rotundiventralis is a small, plankton-eating cichlid found only in the southern end of Lake Tanganyika, where it drifts in slow midwater schools that can number in the thousands. Barely two inches long and almost colorless, it would be unremarkable except for one thing: it practices a rare form of biparental mouthbrooding in which mothers hand part of their brood off to fathers, and genetic work has shown that these mated pairs stay bonded inside the crowd even though no one watching the school can pick the couples out. That hidden pair bond, detected only by DNA, is what makes this otherwise plain fish one of the more quietly remarkable breeders in the lake.

Full Xenotilapia rotundiventralis account →

Sources

  1. tanganyika.si — Xenotilapia rotundiventralis "Cape Nangu"
  2. Xenotilapia rotundiventralis — FishBase summary
  3. Catalog of Fishes (Eschmeyer) — Xenotilapia rotundiventralis
  4. FishBase Field Guide — Xenotilapia rotundiventralis (depth, locality)
  5. Takahashi, Yanagisawa & Nakaya (1997). Microdontochromis rotundiventralis, a new cichlid fish from Lake Tanganyika. Ichthyol. Res. 44(2):109-117
  6. Takahashi, Ochi, Kohda & Hori (2011). Invisible pair bonds detected by molecular analyses. Biology Letters 8(3):355-357