Taxonomy & naming
Maylandia midomo was described in 2013 by Jay R. Stauffer Jr., Kristin E. Black and Adrianus F. Konings, in 'Descriptions of five new species of Metriaclima (Teleostei: Cichlidae) from Lake Malaŵi, Africa,' published in Zootaxa (volume 3647, pages 101–136). It was one of five mbuna named in that paper, and one of two (with Maylandia lundoensis) restricted to Lundo Island in Tanzanian waters at the north-eastern corner of the lake.
The genus name carries a long-running nomenclatural dispute. The species was described in Metriaclima, the genus Stauffer and colleagues coined in 1997 (Greek for 'moderately sloping,' for the head profile). But Maylandia — named in 1984 by Meyer, Riehl and Zetzsche for the German aquarist and author Hans-Joachim Mayland — is the older name and the senior synonym under the priority rule. Eschmeyer's Catalog of Fishes, this atlas's authority for valid names, lists the fish as valid under Maylandia midomo and treats Metriaclima as a synonym; that is the usage here, though much of the European literature and Ad Konings's own books retain Metriaclima.
The epithet midomo is Swahili for 'lips,' chosen because the fish has enlarged, fleshy lips relative to other members of the genus. Within the genus midomo belongs to the rock-dwelling, barred zebra-type assemblage; the describers separated it from sympatric relatives partly on the absence of a black submarginal band in the dorsal fin, together with the distinctive lip development and male colour.
Morphology
Maylandia midomo is a moderately sized mbuna. FishBase records a maximum of 4 in standard length (SL); in the field, males reach about 5 in total length and females are roughly ten per cent smaller. The body is the typical fusiform, moderately compressed mbuna form, with the moderately sloped head and the bicuspid outer-row teeth of the genus. The dorsal fin carries about XVII–XVIII spines and 8–10 (usually 9) soft rays, the anal fin III spines and 7–8 rays.
Its signature feature is in the name: enlarged, fleshy lips, more developed than in its congeners, an adaptation that helps the fish seal against rock and strip the algal film. Colour is the diagnostic male trait — territorial males are blue with green highlights and distinct dark vertical bars, numbering roughly five to nine. Females are duller, blue-green with fainter barring. Unlike several zebra-group relatives, midomo lacks a black submarginal band in the dorsal fin, one of the characters the describers used to set it apart. Egg-spots mark the anal fin of mature males.
Habitat
Maylandia midomo is a Lake Malawi endemic with a very small range, centred on Lundo Island off the north-eastern (Tanzanian) shore; it has also been reported from the nearby Ngkuyo Island. This near-single-island distribution makes it, like its island-mate lundoensis, one of the more narrowly restricted Maylandia.
The species is rock-bound and, in contrast to the silt-tolerant lundoensis, associates mainly with rocks that are largely free of sediment, occurring on the cleaner rocky habitat and only infrequently straying into the shallow intermediate (rock-and-sand) zone. The chemical setting is the standard Lake Malawi envelope: an ancient, strongly buffered rift lake with surface waters around 75–82 °F, alkaline pH of roughly 7.7–8.6, and moderate hardness, stable across the species' small range.
Feeding
Maylandia midomo is an aufwuchs grazer with a second, planktivorous string to its bow. Over the rocks it combs loose material from the algal turf — diatoms and the digestible strands of blue-green algae — using its bicuspid outer teeth, and the enlarged lips that give the fish its name help it work the rock surface. It also schools up into the water column above the rocks to pick plankton, mainly phytoplankton, a dual strategy seen in several zebra-group mbuna.
The practical consequence for aquarists is the familiar one for aufwuchs feeders: a long, plant-adapted gut that copes poorly with rich, high-protein animal foods, and a corresponding susceptibility to 'Malawi bloat.' A spirulina- and vegetable-based diet, supplemented only sparingly, suits the species far better than meaty fare.
Mating
Breeding males of midomo defend cave-centred territories among the rocks, often spaced less than a metre apart — a dense territorial mosaic typical of a productive rocky reef. The male advertises from his cave in full blue-and-barred breeding colour, displaying to females that move through the area, and is strongly aggressive toward rival males, actively excluding them from his patch.
No formal courtship study has been published, but the behaviour follows the standard haplochromine-mbuna sequence: the territorial male leads a receptive female into his cave with lateral displays and shimmying movements, and spawning takes place inside the shelter. Because males are colourful and site-attached while females are cryptic and mobile, mate choice is visual and territory-based.
Breeding
Maylandia midomo is a maternal mouthbrooder. Spawning occurs inside the male's cave: in the classic mbuna sequence the female lays eggs a few at a time and immediately takes them into her mouth, nosing at the egg-spots on the male's anal fin so that fertilisation happens at the mouth, repeating until the clutch is complete. Brooding females then hide among the rocks during the roughly three-week incubation, feeding little, and release the free-swimming fry there, after which parental care ceases.
Clutch size has not been published as a precise figure for midomo; by the pattern of similarly sized zebra-group mbuna it is modest, on the order of a couple of dozen eggs. In the aquarium the cycle replicates readily once a settled male and conditioned females are present; the comparatively large fry accept crushed flake immediately, and moving a brooding female to a quiet rearing tank improves survival in a busy community.
In the aquarium
Maylandia midomo is a specialist's fish — known in the hobby mainly under its 'Lundo Island' locality name, occasionally collected and traded, but far from a mainstream mbuna. Its appeal lies in the clean blue-and-black bars of territorial males and the curiosity of the enlarged lips. Any keeper experienced with Malawi rock cichlids can manage it.
A tank of around 65–80 US gal suits a harem of one male with three or four females, with larger groups possible in correspondingly larger aquaria. Water should be hard and alkaline in the Lake Malawi mould — pH roughly 7.8–8.6, temperature 75–82 °F, moderate to hard general hardness — kept stable with a crushed-coral or aragonite substrate, strong filtration and regular generous water changes; soft, acidic water is unsuitable.
Provide extensive rockwork with caves, which both mimics the clean rocky habitat the fish prefers and disperses aggression by breaking sightlines and multiplying territory edges; a sand base lets females forage and shelter. As with the genus, midomo is markedly aggressive toward conspecific males, so keep a single male and choose robust tankmates of contrasting colour so he does not mistake them for rivals. Diet should be spirulina- and vegetable-based to respect the aufwuchs-grazing gut and avoid bloat — the most common keeping mistake across the guild.
Conservation
The IUCN Red List assessed Maylandia midomo (under Metriaclima) as Near Threatened, with the assessment dated 22 June 2018. Near Threatened, rather than Least Concern, reflects exactly what its biology implies: a near-single-island endemic, restricted essentially to Lundo Island (with a marginal record from Ngkuyo Island), so that any localised pressure falls on the entire known world population at once.
For midomo the most plausible threats are habitat-based. Because it specialises on clean, sediment-free rock, it is arguably more exposed to siltation than its silt-tolerant island-mate lundoensis: sediment loading from catchment deforestation degrades precisely the surfaces it grazes. Localised over-collection for the aquarium trade is a further, if minor, concern. These sit within Lake Malawi's wider trajectory — basin-scale reviews such as Chavula et al. (2023) in the Journal of Great Lakes Research document growing fishing pressure, sediment and nutrient loading, and climate-driven warming that weakens the lake's seasonal mixing. None is recorded as an active decline in midomo, but together they justify the cautious Near Threatened listing for a fish with effectively one place to live.