Taxonomy & naming
Labidochromis sp. "Gigas Chidunga" has no authority, no year of description, and no FishBase entry. It circulates under this informal field name, combining a reference to Labidochromis gigas with its collection locality, Chidunga Rocks. Labidochromis gigas was described by Digby Lewis in 1982 from Likoma Island and is, by IUCN assessment, restricted to just Likoma and Chizumulu Islands (plus translocated populations at Thumbi West Island and Otter Point) — an extent of occurrence of only about 52 mi². Lewis's description anchors a broader "gigas group" of deep-bodied Labidochromis whose males differ only subtly in barring pattern and which field workers have documented from reefs well beyond that tiny core range; Chidunga Rocks, on the Malawian mainland shore, is one such reef, and the form recorded there is kept under an informal sp. designation rather than folded directly into Labidochromis gigas, since its identity relative to the described species has not been confirmed.
Morphology
Labidochromis gigas is the largest species in its genus by a wide margin — FishBase lists a maximum of 4 in standard length, and Konings gives males to about 4.5 in total length in the field, against a genus norm nearer 2.5–3 in. A territorial male gigas is bright iridescent blue, with the head turquoise above and darker below the eye, roughly seven bold dark vertical bars beneath the dorsal fin, green iridescent flecks on the gill cover, and a black snout and interorbital bar in full breeding dress; females and non-displaying males are plain olive-brown with dimmer barring. Members of the wider gigas group are described as near-indistinguishable from true gigas by markings alone, separable mainly by depth preference or locality rather than by any single diagnostic character — which is exactly the position "Chidunga" occupies: presumed gigas-group-typical in size and build, but with no published description confirming its precise colouration or proportions.
Habitat
This form is recorded from Chidunga Rocks, on the Malawian shore of Lake Malawi, well outside the confirmed Likoma/Chizumulu range of true Labidochromis gigas. Labidochromis gigas itself occupies sediment-free rocky habitat, most common between about 6 and 39 ft and recorded across roughly 16–72 ft, occasionally to 98 ft. No depth or micro-habitat figure specific to the Chidunga Rocks population has been separately published, so the range given here reflects the described species' documented envelope. Water conditions follow Lake Malawi's typical hard, alkaline inshore chemistry.
Feeding
Labidochromis gigas departs from the genus's typical crevice-picking habit: Konings and others describe it as primarily algivorous, pinching filamentous algae from small rock pockets and crevices inaccessible to most other herbivores, while also taking small invertebrates living in the same turf. No feeding study exists for the Chidunga Rocks population specifically, so its diet is presented here as gigas-group-typical algivory rather than a separately documented fact for this form.
Mating
Labidochromis gigas males hold and defend a small territory, typically a cave or crevice among the rocks, throughout the year, while females are non-territorial and range freely; the species does not school and tends toward small groups or a loose harem of one male with several females. A conditioned male intensifies into full blue display, the black snout and interorbital bar sharpening, and courts passing females with the standard haplochromine routine of fin-spread and quivering display. Whether "Gigas Chidunga" follows this same territorial pattern, and any courtship detail specific to it, have not been separately documented.
Breeding
Like all mbuna, Labidochromis gigas is a maternal mouthbrooder, with the female laying a modest clutch — on the order of a couple of dozen eggs, befitting a fish of this size — and brooding the developing young in her mouth for about three weeks before releasing free-swimming fry among the rocks. "Gigas Chidunga" is presumed to follow the same pattern by group resemblance, though no clutch size or brooding data specific to this population have been separately published.
In the aquarium
Labidochromis sp. "Gigas Chidunga" is not a common hobby fish; even the formally described Labidochromis gigas appears mainly in specialist Malawi cichlid circles rather than general fish shops, and members of the wider gigas group circulate still less often. A keeper who did obtain it should plan for the largest species-typical build in the genus: a tank of at least 47 in with substantial rockwork offering caves and crevices, hard alkaline water at roughly pH 7.8-8.6 and 75–79 °F, and a diet leaning toward spirulina-based flake or pellet with vegetables and only modest amounts of frozen animal food, since gigas and its group are described as more predatory and aggressive than most Labidochromis and prone to Malawi bloat on a too-rich diet. A harem of one male with two or three females, kept apart from delicate or fry-sized tankmates the fish may prey on, is the standard approach.
Conservation
Labidochromis sp. "Gigas Chidunga" has no IUCN Red List assessment, since formal evaluation requires a validly published scientific name and none exists for this form. Labidochromis gigas itself is assessed Least Concern, an upgrade from a 2006 Vulnerable listing based on its tiny two-island range, but that status describes a population confined to Likoma and Chizumulu and cannot be extended to a separate mainland-shore form at Chidunga Rocks. As a rock-associated cichlid of the gigas group, it shares the general exposures documented across Lake Malawi's rocky-reef endemics — sedimentation from catchment erosion, localised habitat disturbance, and ornamental collecting — but no population-specific data exist to characterise its status further.