Taxonomy & naming
Pseudotropheus sp. "Polit Tumbi" is undescribed: no holotype, no publication, no entry in Eschmeyer's Catalog of Fishes. The trade name follows the same base epithet as the better-documented Pseudotropheus sp. "Polit", whose type population comes from near Lupingu on the Tanzanian shore, with a further population at Lion's Cove; a widely repeated attribution to Warren E. Burgess in Konings' Malawi Cichlids in their Natural Habitat (4th ed., 2007) is a nomen nudum — a name published in a popular hobby book without meeting ICZN requirements — and has no standing in zoological nomenclature. The Tumbi Point population sits at the southern end of the lake's central-western Mozambican coast, geographically distant from the Tanzanian Polit sites, and shares the collecting locality of Chindongo (formerly Pseudotropheus) socolofi, whose documented native range runs roughly from Cobwe to Tumbi Point along this same stretch of coast. Whether "Polit Tumbi" is the same species as the Tanzanian Polit complex, a related but distinct undescribed form, or an unrelated fish that happens to share a descriptive trade name is not resolved in any source available here. Its name should also not be confused with "Thumbi" (Thumbi Point and Thumbi West Island, both in the Malawian waters of Lake Malawi National Park) — a near-identical spelling that has already caused confusion for other Polit-complex populations in hobby literature. Generic placement follows Pseudotropheus Regan, 1922, provisionally; the 2016 revision that created Chindongo for the Pseudotropheus elongatus group did not include this form. The base epithet "polit" is of uncertain derivation — some hobby sources trace it to Greek politikos or Latin politus, an ironic nod to the complex's outsized aggression, but this is unconfirmed and, since the name has no formal standing, not settled by any authority.
Morphology
This form follows the compact, laterally compressed mbuna body plan typical of the genus, with a moderate body depth and protrusible jaws suited to rasping aufwuchs from rock. Colour has not been independently documented for the Tumbi Point population specifically. If it follows the pattern reported for the Tanzanian Polit complex, dominant males would be expected to show an icy, pale to near-white blue body with a contrasting dark face mask across the snout and cheeks, egg-spots on the anal fin, and a strongly rank-dependent colour switch in which a deposed male reverts toward plain brown within hours — but this should be read as an expectation drawn from a geographically distant relative of the same trade name, not a confirmed description of the Tumbi Point fish. Genus-typical adult length runs roughly 3–4.5 in.
Habitat
Pseudotropheus sp. "Polit Tumbi" is recorded from Tumbi Point, a rocky site on the Mozambican shore of Lake Malawi, within the same general stretch of coast — running from around Cobwe to Tumbi Point — documented as the native range of Chindongo socolofi. Like other rock-dwelling mbuna it is expected to hold territory among boulders and crevices in the shallow-to-intermediate littoral zone rather than crossing open sand, the isolating mechanism that lets closely related, similarly named forms diverge along the same general coastline. Water chemistry follows the Lake Malawi norm: warm, hard and alkaline, typically 75–82 °F and pH 7.7–8.6.
Feeding
As with other Pseudotropheus, this form is presumed to be an aufwuchs grazer, rasping the mixed mat of filamentous algae, diatoms and small invertebrates from sunlit rock surfaces. No feeding study specific to this population exists, but this diet is close to universal across rock-dwelling mbuna in the genus, including the better-studied Tanzanian Polit populations, which are documented as vegetable-matter grazers with no evidence of piscivory or sand-sifting.
Mating
Breeding behaviour is presumed to follow the standard mbuna pattern: polygynous and territorial, with a dominant male holding rock and displaying to attract passing females rather than pairing exclusively. In the better-documented Tanzanian Polit complex, males are reported as unusually intolerant of rival males and, unusually for mbuna, persistently harassing females between spawning bouts — a trait that has led hobbyists to recommend a high female-to-male ratio. Whether this behavioural intensity applies to the Tumbi Point population specifically has not been documented, so this account notes it as a pattern in a related population rather than a confirmed trait here.
Breeding
Pseudotropheus sp. "Polit Tumbi" is presumed to be a maternal mouthbrooder, as is standard across the genus. The Tanzanian Polit complex is documented brooding for roughly 24 days at aquarium temperatures, on modest clutches in the range of 30–35 eggs, with fry large enough to take newly hatched brine shrimp immediately on release. No brooding data specific to the Tumbi Point population exists, so these figures should be read as a genus-level and complex-level expectation rather than a measurement of this fish.
In the aquarium
Pseudotropheus sp. "Polit Tumbi" should be kept as a standard rock-dwelling mbuna, and given the general rarity of Polit-complex fish in the trade, verifying correct identification and provenance at purchase matters more than usual. Dense, stable rockwork built into a tank of at least 47–59 in gives a territorial male room to hold ground away from females and any rival males; a sand or fine gravel substrate suits the setup. Water chemistry should replicate Lake Malawi: 75–82 °F, pH 7.7–8.6, consistently hard and alkaline. Diet should be predominantly vegetable-based — a spirulina-forward flake or pellet as the staple — since high-protein foods are poorly tolerated by algae-grazing mbuna and are strongly implicated in the digestive illness known as Malawi bloat. Keep a generous surplus of females per male, since related Polit-complex populations are documented as persistently harassing females, and never mix this form with Chindongo socolofi or other similarly patterned mbuna from the same Tumbi Point reef, since mbuna hybridise readily and the resulting offspring would compromise the provenance that gives a locality form like this its value.
Conservation
No IUCN Red List assessment exists for Pseudotropheus sp. "Polit Tumbi", and none can while it remains formally undescribed; no status, category or year should be attached to it. As a mbuna apparently restricted to a single named reef on the Mozambican shore, it carries the general vulnerability shared by narrow-range rock-dwelling cichlids around Lake Malawi — dependence on a small patch of intact rocky habitat and exposure to localised over-collection for the ornamental trade — but no population-specific study documents its actual abundance or trend. The accurate statement is that it is unevaluated.