Taxonomy & naming
Pseudotropheus sp. "Lucerna Blue Mozambique" is an informal, undescribed taxon: it has no describing author, no publication date, and no entry in Eschmeyer's Catalog of Fishes. The trade name follows the usual pattern for undescribed mbuna — genus, "sp." to mark it as unnamed, then a descriptive tag combining colour and locality. "Lucerna" is used in the aquarium trade as a name element for a small number of Pseudotropheus-group forms; its precise origin is not well documented in the sources available to us, and this article does not assert a specific etymology beyond noting the convention. "Blue" reflects the ground colour reported for breeding males, and "Mozambique" specifies the collection locality — the Mozambique coast of the lake around Chuanga and Metangula, with an additional record at Gome on the Malawi side. It should be treated strictly as a locality-based, informally recognised form pending formal taxonomic study.
Morphology
This form follows the standard Pseudotropheus body plan: a moderately elongate, laterally compressed body with the robust, specialised dentition — an outer row of bicuspid or unicuspid teeth over inner rows of tricuspid teeth — used across the genus to graze algae from rock surfaces. Its trade name identifies blue as the defining colour of breeding males, consistent with the blue ground colour common across many Pseudotropheus and allied mbuna, though the specific pattern details — barring, fin colour, and how strongly females differ from males — have not been documented in detail for this population in the sources available to us. Size is not separately documented for this form and is presumed to sit within the genus-typical Pseudotropheus range of roughly 3–4.5 in.
Habitat
Pseudotropheus sp. "Lucerna Blue Mozambique" is documented along the Mozambique shore of Lake Malawi at Chuanga and Metangula, with a further record at Gome on the Malawian side — a stretch of the central-southern lake with rocky shoreline habitat typical of the mbuna zone. Like other Pseudotropheus, it is expected to hold territory among rocks and crevices in shallow-to-intermediate depths rather than ranging onto open sand. Water conditions here match Lake Malawi generally: warm, hard, and strongly alkaline.
Feeding
As with other Pseudotropheus, this form is expected to be a specialised algae grazer, rasping the Aufwuchs — the mat of filamentous algae and its associated diatoms and small invertebrates — from rock surfaces using the genus's characteristic dentition. No feeding study specific to this population has been published, but this diet is essentially universal across rock-dwelling mbuna in the genus. The Aufwuchs mat itself is not a single food type but a mixed community of filamentous green algae, diatoms, cyanobacteria, and the small invertebrates that live within it, and different mbuna species partition this resource by grazing angle, bite force, and preferred rock texture rather than competing head-on for an identical diet. Dense mbuna populations can crop the algal turf on a favoured rock down to a fine stubble, and territorial males often defend a feeding patch as fiercely as a spawning site, since a well-grazed rock represents a defensible, renewable food source rather than a one-off meal.
Mating
Breeding in Pseudotropheus is polygynous and territorial: males hold rock or crevice sites and display to females, who visit rather than pair-bond with a given male. No behavioural account specific to this population has been published, so its mating system is inferred from the genus as a whole rather than documented directly for the Mozambique population. Courtship follows the conventional haplochromine sequence: a territorial male performs a quivering lateral display in front of a visiting female, leading her toward his spawning site if she is receptive. The male's anal fin typically carries egg-spot markings — round, egg-like blotches — that the female is drawn to peck at after depositing her own eggs, a mechanism that draws sperm into her mouth and fertilises the clutch she is already holding. A dominant male may court and spawn with several females in the course of a single day, and females themselves show no lasting preference for one male over another beyond his current colour and territory quality.
Breeding
Pseudotropheus sp. "Lucerna Blue Mozambique" is presumed to be a maternal mouthbrooder, as are all members of the genus. Following spawning at a male's territory, the female takes the fertilised eggs into her mouth and incubates them there, foregoing normal feeding for much of the brooding period before releasing free-swimming fry with no further parental care from the male. Clutch size and brooding duration have not been documented for this specific form. At Lake Malawi's stable warm temperatures the female typically broods for roughly three to four weeks, during which she retreats into rock crevices for shelter and largely stops feeding, drawing on body reserves to see the clutch through development. Fry are released as fully formed, free-swimming miniatures able to feed independently from the moment of release, and they immediately seek cover among rocks to avoid predation, including from adult cichlids of their own species. There is no further parental care once the fry are released, and a healthy female can produce several broods per year under stable conditions.
In the aquarium
"Lucerna Blue Mozambique" is a locality-specific form kept mainly by aquarists interested in Mozambique-coast Pseudotropheus populations rather than a mainstream mbuna offering.
As with the genus generally, a tank furnished with dense rockwork and abundant broken sightlines suits its territorial, algae-grazing habits, and stocking several females per male reduces the harassment a single female would otherwise face from a constantly displaying territorial male. A tank of at least 47 in gives room for multiple territories among tankmates. Water should match Lake Malawi conditions: warm, hard, and clearly alkaline, since prolonged exposure to soft or acidic water causes chronic problems in mbuna.
Diet should be predominantly vegetable-based — a quality spirulina-based flake or pellet, supplemented occasionally with blanched vegetables — since high-protein foods are poorly tolerated by algae-grazing mbuna and increase the risk of bloat. Given the resemblance of many blue Pseudotropheus forms to one another, keepers wanting to preserve a pure Mozambique-coast line should avoid mixing this form with other blue mbuna of uncertain provenance.
Conservation
Pseudotropheus sp. "Lucerna Blue Mozambique" has no IUCN Red List assessment, because it has never been formally described and has no valid scientific name available to be assessed. This is a statement about taxonomic status, not population health. As a rock-restricted mbuna along a collected stretch of the Mozambique shore, it faces the general pressures common to Lake Malawi's ornamental cichlids, but no dedicated population data exists to characterise its actual conservation status. Because Lake Malawi's mbuna are typically confined to narrow, rock-specific home ranges and rarely cross expanses of open sand, a locality-restricted form like this is inherently more exposed to over-collection or localised habitat disturbance than a wide-ranging species would be, even though the lake as a whole supports enormous numbers of related mbuna.