Taxonomy & naming
Maylandia sp. "Lime" carries no describing author, no publication date, and no entry under a validated name in Eschmeyer's Catalog of Fishes. It is an informal trade designation, named — as is standard for undescribed mbuna — for the distinguishing feature of male breeding colour, here a lime-green tone. The genus Maylandia, honouring the German aquarium author Hans J. Mayland, comprises the group of mbuna long known informally as the "zebra" complex, famous for producing dozens of visually distinct, locally endemic colour forms around individual islands and reefs across Lake Malawi — nowhere more so than around Likoma Island, whose surrounding islets and points have yielded an unusually dense concentration of named Maylandia forms. No formal taxonomic study has established which described Maylandia species this Lime form is most closely related to, or whether it in fact represents a distinct, reproductively isolated lineage rather than a colour variant of a described species; it should be treated as an unresolved, locally distinct entity pending that work.
Morphology
As implied by its trade name, breeding males of Maylandia sp. "Lime" are described as showing a lime-green body colour, distinguishing this form from the blue- and yellow-dominant colour patterns typical of most other Maylandia forms around Likoma Island. Beyond that documented colour cue, detailed morphometric data have not been published for this population. The body should be expected to show the moderately deep, laterally compressed shape typical of zebra-type Maylandia, rather than the slender build of the elongatus group. Genus-typical size runs to roughly 3.5–4.5 in total length, with males somewhat larger than females. Sexual dichromatism is expected to be pronounced, as throughout the genus, with females duller and less strongly marked than the lime-toned males.
Habitat
The form is recorded from a small cluster of localities immediately around Likoma Island, in the open water of central Lake Malawi: Maingano Island, the Mbamba Islands, and Membe Point. This island group, isolated from the mainland shore by considerable stretches of deep water, hosts one of the lake's densest concentrations of narrowly endemic mbuna forms, each confined to a single islet or short stretch of coast. Habitat for zebra-type Maylandia is typically shallow rocky shoreline and boulder fields, generally within the top 33–49 ft, where males hold territories on exposed rock faces. The surrounding water is warm, hard, and alkaline, consistent with Lake Malawi's rocky littoral throughout.
Feeding
Maylandia species are algae grazers, using specialised dentition — fine, closely packed teeth arranged for scraping and shearing rather than crushing — to remove filamentous algae and the associated aufwuchs community of diatoms and micro-invertebrates directly from rock surfaces. Productive grazing patches are a contested resource on a crowded reef, and mature fish typically defend favoured feeding territories from both conspecifics and other algae-grazing mbuna species sharing the same rock face. Around Likoma Island, where several distinct Maylandia forms coexist on adjacent stretches of reef, this kind of territorial feeding behaviour is a familiar sight to divers and collectors. Maylandia sp. "Lime" is presumed to follow this genus-typical feeding pattern, though no dedicated feeding study has been published for this specific population.
Mating
Mature males of this form are expected to establish and defend feeding-and-breeding territories on the rock face, displaying their lime-toned breeding colour to attract passing females, in keeping with the general Maylandia pattern. Courtship follows the standard haplochromine sequence seen throughout Lake Malawi's mouthbrooding cichlids, centred on the egg-spot markings carried on the male's anal fin, which the female pecks at during spawning as she collects the real eggs into her mouth. No locality-specific behavioural account exists for this population. Rival males on adjacent territories frequently engage in ritualised displays and occasional physical confrontation over boundary disputes, a common feature of dense mbuna reefs where suitable breeding rock is limited; around Likoma Island, where several distinct Maylandia forms are packed onto neighbouring stretches of coast, this kind of territorial contest likely occurs both within and between differently coloured populations, though no study has documented the specific dynamics for this Lime form.
Breeding
Reproduction follows the standard Lake Malawi haplochromine pattern of maternal mouthbrooding: the female alone carries the fertilised eggs and subsequent fry in her mouth, without normal feeding, for roughly three to four weeks before releasing free-swimming young able to feed and shelter independently. Brooding females typically retreat from open feeding territories into crevices or quieter parts of the reef for the duration, a behavioural shift that reduces both feeding opportunity and exposure to territorial males. The male provides no further parental role once spawning is complete and does not guard the eggs, fry, or female. Clutch sizes in Maylandia mbuna are typically modest, on the order of a few dozen eggs, in line with other small mbuna species; exact figures have not been documented for this Likoma-area population.
In the aquarium
Maylandia sp. "Lime" would be kept as a standard zebra-type mbuna: a tank with abundant rockwork arranged into caves and broken sightlines, a sand substrate, and water chemistry matching Lake Malawi's rocky zone — hard and strongly alkaline, pH roughly 7.7 to 8.6, temperature 75–82 °F. As with most Maylandia, males can be territorial and aggressive toward similarly patterned tankmates, so keeping one male with several females, or stocking carefully within a larger, well-decorated mixed-mbuna community, is the safer approach. Diet should lean vegetable — a spirulina-based flake or pellet — supplemented sparingly with small invertebrates, avoiding fatty, protein-heavy foods that predispose Malawi mbuna to digestive bloat.
Conservation
Maylandia sp. "Lime" has not been evaluated by the IUCN and, as an undescribed form, has no Red List status. Its documented range is limited to a small cluster of localities immediately around Likoma Island. Like the many other narrowly endemic Maylandia forms concentrated in this island group, it is inherently exposed to the risks that come with a small range — concentrated collection pressure, localised habitat disturbance, or chance events affecting a single reef or islet — even though no specific threat has been documented for this population. Several formally described Maylandia species have themselves been assessed by the IUCN as threatened or near-threatened, generally on the basis of extremely restricted ranges rather than any single acute threat, which illustrates how vulnerable this style of narrow-endemic mbuna radiation can be in principle even where the aquarium trade itself is not the primary driver of concern.