Taxonomy & naming
Protomelas sp. "Johnstoni Solo" is an undescribed Lake Malawi haplochromine, recognised only by this trade name on the malawi.si database and in the specialist hobby. It has no valid scientific name, no describing author, and no publication date, and none should be attached to it. The "sp." plus quoted-name format signals a field-recognised but taxonomically undiagnosed population, following the standard convention for Malawi's many undescribed cichlids.
The first element of the name, "Johnstoni," borrows the epithet of Protomelas johnstoni (Günther, 1893), a formally described species named for Sir Harry Hamilton Johnston, the British colonial administrator, explorer, and naturalist whose surveys of the Lake Malawi region in the 1890s brought back some of the earliest specimens studied by British Museum ichthyologists. Its use here signals that this form is regarded as resembling or closely allied to P. johnstoni, not that the two have been confirmed as the same species. The second element, "Solo," is not explained in any source consulted for this article; its precise meaning — whether locality, collector, or a descriptive reference — is not established.
Protomelas was erected by Trewavas in 1935 and today comprises a large and ecologically varied group of Lake Malawi haplochromines, several of which — including the P. johnstoni and P. taeniolatus complexes — are prominent in the aquarium trade for their striking male breeding colours.
Morphology
No published measurements or colour account specific to Protomelas sp. "Johnstoni Solo" were found in the sources consulted here. Genus context: Protomelas species in the johnstoni group are moderately deep-bodied, laterally compressed haplochromines, larger than the mbuna, with adult males of related described forms commonly reaching the mid-to-high teens of centimetres — a figure offered as a genus-typical estimate for this form rather than a confirmed measurement.
The described relative P. johnstoni develops blue body colouration in breeding males, with fin colour that can include red or orange elements, against a more subdued silvery-brown in females and non-breeding males. Whether this specific population matches that pattern, and how closely, has not been documented in the sources available here and should not be presumed beyond the name's implied resemblance.
Habitat
The four documented localities for this form — Makonde, Matema, Nkanda, and Pombo Rocks — span roughly 81 mi of the Tanzanian shore of northern Lake Malawi, from Matema and Nkanda in the north down to Pombo Rocks further south. This is a considerably wider spread than is typical for a single mbuna trade form, consistent with the more mobile, less strictly rock-bound habits of many non-mbuna haplochromines like Protomelas.
Species in the P. johnstoni group are generally associated with rock and adjacent sand rather than the pure rock specialisation of mbuna. Lake Malawi's water chemistry in this zone runs broadly 24-28 degC and pH 7.7-8.6, hard and alkaline, with habitat for mid-sized haplochromines of this kind typically found from a few metres to about 82 ft depth. No site-specific depth record exists for this particular form.
Feeding
Feeding has not been documented specifically for this form. The Protomelas johnstoni group is generally understood as a generalist forager over rock and sand margins, picking aufwuchs and small benthic invertebrates rather than specialising narrowly in either, a diet broadly consistent with the wider genus. Without a dedicated study of this population, that genus-typical generalist description is the most that can be responsibly offered.
Unlike the specialised, comb-toothed dentition of mbuna, Protomelas in this group carries more generalised jaw teeth suited to picking varied food items rather than scraping a fixed algal turf, consistent with its wider-ranging, less territorial feeding habits over sand and rock margins.
Mating
Social behaviour has not been documented specifically for this form. Protomelas, like other Lake Malawi haplochromines, is understood to be polygynous, with breeding males establishing and defending display territories — typically over rock or adjacent sand — that they hold to attract passing females in a lek-like arrangement rather than forming pair bonds. Females move between territories and are not themselves territorial. No detail specific to this population's courtship behaviour has been published.
Courtship in this style of haplochromine typically involves the male performing a quivering lateral display and leading an approaching female toward his spawning site, a pattern shared broadly across the lake's mouthbrooding cichlids regardless of habitat. Because territories away from strict rock habitat are often less permanent than a mbuna's defended cave, a displaying male may relocate his site if local conditions change — a detail not documented specifically for this population but consistent with the wider ecology of lek-breeding, sand-associated haplochromines.
Breeding
As with every Lake Malawi haplochromine, this form is presumed to be a maternal mouthbrooder. A female takes eggs into her mouth at the male's territory, is drawn to fertilise them by mouthing the egg-spot markings on his anal fin, and broods the clutch orally for roughly three to four weeks before releasing free-swimming fry, with no further parental involvement afterward. No clutch size has been documented for this specific form; genus-typical broods for mid-sized Protomelas are expected to run to several dozen eggs.
The egg-spot mechanism behind this process is one of the more distinctive features of Lake Malawi cichlid biology: the yellow-orange markings on the male's anal fin closely mimic the fish's own eggs in size and colour, and the female's instinct to gather stray eggs into her mouth is what draws her toward the male's vent, where she takes in sperm instead. This indirect fertilisation method, shared across virtually the entire haplochromine radiation of the lake, lets fertilisation happen without either fish releasing gametes into open water where they would be exposed and vulnerable.
In the aquarium
Protomelas sp. "Johnstoni Solo" is an uncommon trade fish, more likely to be found through specialist Malawi cichlid importers than general retail. No form-specific husbandry literature exists, so the guidance here follows general practice for mid-sized, sand/rock-associated Protomelas.
A tank of at least 59 in is appropriate given the genus's larger adult size, aquascaped with open sand and scattered rock rather than the dense wall-to-wall rockwork of a pure mbuna setup. Water must replicate Lake Malawi's chemistry: hard and alkaline, pH roughly 7.8-8.6, temperature 24-28 degC. Diet should include a quality cichlid pellet as a staple, supplemented with frozen or live invertebrates such as chironomid larvae, brine shrimp, and daphnia.
A single male with several females is the standard low-conflict arrangement for a lek-breeding haplochromine of this kind; unlike mbuna, males of this group are generally more tolerant of dissimilar tankmates, though aggression toward closely related or similarly coloured species should still be expected. As with all undescribed locality forms, keep it apart from other Protomelas populations, and especially from other johnstoni-allied forms, to prevent hybridisation.
Conservation
Protomelas sp. "Johnstoni Solo" has never been formally described and carries no IUCN Red List assessment of any kind; evaluation requires a valid scientific name. Its documented range along a substantial stretch of the Tanzanian shore shares the general pressures facing Lake Malawi's inshore habitat: sedimentation from catchment disturbance, warming surface waters, and the cumulative effects of the region's fisheries. Formal description would be the prerequisite for any future Red List evaluation; until then its status is properly recorded as unassessed.
The wider Lake Malawi cichlid fauna is already recognised as under pressure: the lake's fisheries and freshwater ecosystems face documented stress from catchment deforestation, agricultural runoff, and a warming, increasingly stratified water column, problems that fall on described and undescribed cichlids alike regardless of their taxonomic status. A trade name and a place in the aquarium hobby are not a substitute for formal assessment, but they do mean this form's population is at least being watched by people with a direct interest in its continued survival at its collection sites.