Taxonomy & naming
Pseudotropheus sp. "Variable Eastern" is not a formally described species. It has no scientific name of its own, no describing author, no year of publication, and no entry in Eschmeyer's Catalog of Fishes, because no taxonomist has published a description establishing it. It is an informal taxon recognised in the field and aquarium literature, principally through Ad Konings's documentation of the southern lake's Malawi-Mozambique shoreline. The placeholder name follows the standard convention for undescribed cichlids that lack one single, fixed colour character to name: the genus Pseudotropheus, the abbreviation "sp." (species), and the descriptive tags "Variable," flagging that male colouration is reported to differ noticeably between individuals rather than following one pattern, and "Eastern," for its position on the lake's eastern side at Gome and Meponda. This kind of variability is itself a recognised feature in several Lake Malawi mbuna populations, some of which resemble more than one named form depending on the individual fish, complicating identification. Until a revision addresses this population directly it should be treated strictly as a Konings-recognised undescribed form, and no authority or date should be attached to it.
Morphology
Pseudotropheus in its modern sense comprises robust-bodied, moderately elongate mbuna with a blunt head and comb-like unicuspid teeth for algae grazing. Genus-typical adult size runs roughly 3–4.5 in; no formal measurement exists for this population specifically. True to its trade name, breeding male colouration is reported to vary between individuals rather than following a single fixed pattern; no consistent, verified colour description can therefore be given here without overstating what is documented, beyond noting that this variability is itself the population's defining feature. Females and subordinate males are expected to be plainer, in the typical mbuna pattern of duller, more cryptic non-dominant colouration.
Habitat
This form is recorded from Gome, on the Malawian shore, and Meponda, on the Mozambican shore, both in the southern part of Lake Malawi on opposite sides of the international boundary that crosses this stretch of coast. As with other Pseudotropheus, it is expected to be strictly rock-associated, grazing algal films from rock surfaces in the shallow-to-moderate depths typical of mbuna habitat. The water column here follows the lake-wide profile: warm, alkaline, and well-buffered, broadly mid-20s Celsius with pH on the alkaline side of neutral. As an undescribed, locality-based form its precise depth range and full distribution beyond the Gome–Meponda area are not established.
Feeding
Pseudotropheus as a genus are specialised algae grazers, using comb-like unicuspid teeth arranged in tight rows to scrape algal films and the associated small invertebrates ("Aufwuchs") from rock surfaces in well-lit water. This grazing mode ties the fish to hard, sunlit rock rather than sand or open water, and at Gome and Meponda it would put the fish in direct competition with the dense, mixed mbuna assemblages typical of these southern-lake rocky shores. No feeding study exists for this population specifically, but this genus-typical herbivore/detritivore mode is the reasonable characterisation absent contrary data.
Mating
Like other Lake Malawi mbuna, this form is presumed polygynous, with males holding and defending small territories on the rock face, courting passing females from these sites while driving off rival males. There is no pair bond. Females move between male territories, choose largely on colour and site quality, and spawn briefly on the rock before departing with the fertilised clutch in the mouth. Whether the population's reported colour variability affects female mate choice has not been studied; the account here follows the general pattern documented for Pseudotropheus and rock-dwelling mbuna more broadly.
Breeding
Pseudotropheus sp. "Variable Eastern" is a maternal mouthbrooder, as are all Lake Malawi mbuna. After spawning on the rock face, the female carries the fertilised eggs in her mouth for roughly three weeks, feeding little during this period, before releasing free-swimming fry with no further care from either parent. Clutch size has not been documented for this form specifically; by analogy with similarly sized Pseudotropheus species, a modest clutch — likely a few dozen eggs — is a reasonable expectation rather than a measured fact.
In the aquarium
Pseudotropheus sp. "Variable Eastern" is an uncommon aquarium fish, traded mainly through specialist importers working the southern Malawi-Mozambique shoreline. Where it is kept, husbandry follows the well-established mbuna template.
Dense, stable rockwork built directly on the tank floor is essential, since this is a strictly rock-associated grazer needing abundant surface area and shelter. A footprint of at least 47 in suits an adult group. Water chemistry should mirror Lake Malawi's profile: temperature in the mid-20s Celsius, pH roughly 7.7–8.6, and well-buffered water, with prolonged soft or acidic conditions avoided. Diet should emphasise vegetable matter — a good spirulina-based flake or pellet as the staple, with algae wafers and blanched vegetables as supplements — reflecting its herbivore/grazer biology; protein-heavy foods should be limited, as herbivorous mbuna are prone to digestive problems on rich diets. As with other mbuna, males are territorial and often aggressive, so a single male with multiple females and adequate rockwork to break sightlines works better than a pair in a small tank. Because individual males can look markedly different from each other, keepers who want a documented, consistent line should source stock from a single collection event rather than mixed imports.
Conservation
Pseudotropheus sp. "Variable Eastern" has not been evaluated by the IUCN, and as an undescribed form without a formal scientific name it has no Red List assessment of any kind. That silence is a statement about taxonomy, not about safety. As a population spanning the Malawi-Mozambique boundary in the southern lake, it faces the general pressures affecting that stretch of shore: ornamental collection and the broader basin-wide stresses of sedimentation and fishing pressure, with the Mozambican side generally less intensively surveyed than the Malawian shore. No conservation status should be fabricated for it. The honest statement is that it is unassessed and that its true range and status remain to be established by formal study.