Taxonomy & naming
Labeotropheus artatorostris was described by Michael J. Pauers in 2017, in 'A New Species of Labeotropheus (Perciformes: Cichlidae) from Southern Lake Malaŵi, Africa' (Copeia 105(2):399–414). FishBase (species 69289) and Eschmeyer's Catalog of Fishes list it as valid in the family Cichlidae, subfamily Pseudocrenilabrinae.
For decades the genus Labeotropheus contained only Ahl's Labeotropheus fuelleborni (1927) and Trewavas's Labeotropheus trewavasae (1935). Pauers's work argued that isolated rocky reefs across Lake Malawi each harbour distinct Labeotropheus populations, separable by male nuptial colour and by fine snout and body proportions. Labeotropheus artatorostris was among the first of these formal splits, following close on the 2016 descriptions of Labeotropheus simoneae and Labeotropheus chlorosiglos. The epithet combines Latin artatus, 'narrowed' or 'compressed,' with rostrum, 'snout' — a reference to the short, tightly built snout pad that the author found diagnostic. As a recent split it has no established trade name.
Morphology
Labeotropheus artatorostris shows the genus hallmark: a thick, fleshy snout overhanging an inferior, subterminal mouth, the apparatus that lets these fish hold their bodies parallel to the rock while rasping algae. What sets this species apart, and gives it its name, is that the snout pad is comparatively short and compressed rather than long and projecting — a subtle but consistent difference from neighbouring forms. It is a robust, relatively deep-bodied member of the genus.
Detailed maximum-size figures for this species are sparingly reported; it sits within the normal Labeotropheus range of roughly 3–4.5 in standard length, a small to mid-sized mbuna. Breeding males carry the bright blue ground colour typical of the genus with species-specific fin markings, while females show the muted grey, orange-flecked pattern usual for female mbuna. As with the rest of the recently split Labeotropheus, it is the male's breeding livery, defended over a home reef, that most reliably distinguishes it.
Habitat
Labeotropheus artatorostris is endemic to Lake Malawi, with a type locality at Mumbo Island (roughly 13.99° S, 34.76° E) in the southern part of the lake, within the Lake Malawi National Park region. Like the other modern Labeotropheus splits it appears to be a narrow-range, island-associated form rather than a lake-wide species.
The habitat is the standard mbuna biotope: rocky, algae-covered shoreline and island slopes where strong light and wave action sustain a thick film of filamentous algae over the boulders. The water is hard and alkaline — pH about 7.7–8.8 and temperatures of roughly 75–82 °F, the Rift-lake chemistry Lake Malawi is known for. Robust Labeotropheus of this kind are typically tied to the turbulent, well-oxygenated shallows.
Feeding
This is a committed algae-scraper. The overhanging fleshy snout and inferior, subterminal mouth — and in this species the notably short snout pad — let it press its jaws flat to the rock and rasp the tough Aufwuchs, the felt of filamentous algae and the small invertebrates within it, while keeping its body almost horizontal. This grazing posture is the functional signature of the whole genus.
No feeding study specific to Labeotropheus artatorostris has been published; its diet is inferred from its anatomy and from the well-documented ecology of Labeotropheus. In captivity it should be kept as a herbivore: vegetable- and spirulina-based foods and grazing surfaces, with protein-rich foods minimised to avoid the digestive bloat that herbivorous Malawi cichlids suffer.
Mating
Like virtually all Lake Malawi mbuna, Labeotropheus artatorostris is polygynous and non-pair-forming. A dominant male defends a rocky territory, intensifies into breeding colour, and courts ripe passing females, while subordinate males and females keep the duller pattern. Indeed, the entire case for splitting the genus rests on the consistency of male nuptial colour over a home reef.
Species-specific courtship has not been formally observed, but it is expected to follow the mbuna norm: a quivering lateral display by the male, the female led to a cleared spot on the rock, and spawning conducted without any lasting pair bond. Males are territorial and intolerant of rivals.
Breeding
Labeotropheus artatorostris is a maternal mouthbrooder. The female lays a small clutch, immediately mouths the eggs, and — cued by the egg-spot dummies on the male's anal fin — takes in his milt to fertilise the brood she already carries. The male has no further role.
No brood counts or incubation times have been published for this species. By the pattern of similar Labeotropheus, a female would be expected to carry the clutch for around three weeks before releasing free-swimming fry, brooding without feeding throughout, with the fry grazing almost immediately on release. These remain honest gaps in the record for a recently described fish rather than measured figures.
In the aquarium
Labeotropheus artatorostris is uncommon under its own name in the hobby; most aquarium Labeotropheus still circulate under the old fuelleborni and trewavasae labels or by collecting locality. Where it is kept, it needs the standard robust-Labeotropheus setup: a spacious, rock-built Malawi tank with hard, alkaline water (pH above 7.7), temperatures around 75–82 °F, and a sand floor beneath piled rock that breaks sight lines.
It is a vigorous, territorial mbuna best housed with other robust Malawi rock-dwellers and with enough females to diffuse male aggression. As a dedicated grazer it requires a vegetable-based diet; high-protein foods invite bloat. One caution applies across the genus: Labeotropheus hybridise readily in captivity, and because the species are diagnosed largely on male colour, mixing island forms or other mbuna produces fish of no scientific or conservation value. Keep a single species of known provenance to maintain it true.
Conservation
Labeotropheus artatorostris has not been assessed by the IUCN Red List, so it carries no formal conservation status. As a narrow-range, island-associated endemic, it is the kind of fish most exposed to localised pressures, though its southern-lake range falls near the protected waters of Lake Malawi National Park.
The wider setting is the one shared by all Malawi rock-dwellers. The Chavula et al. (2023) review of the Lake Malawi/Niassa/Nyasa basin documents over-fishing, sediment and nutrient loading from deforested catchments, surface-layer warming, and a growing invasive-species risk. For an algae-grazing mbuna the key danger is sedimentation, which smothers the rock surfaces and the algal film the fish depends on. The honest summary is that Labeotropheus artatorostris is unassessed and narrowly distributed — a combination warranting caution rather than complacency.