Taxonomy & naming
Stigmatochromis pleurospilus was described by the British ichthyologist Ethelwynn Trewavas in her landmark 1935 synopsis of Lake Nyasa cichlids, published in the Annals and Magazine of Natural History. She originally placed it in the broad catch-all genus Haplochromis as Haplochromis pleurospilus, on the basis of a single immature specimen of 1.5 in standard length — the holotype, catalogued as BMNH 1935.6.14.1475 and still held at the Natural History Museum, London — collected by the Colonial Office naturalist Cuthbert Christy during his 1925–26 survey of the far northern lake shore at Lupembe Sandbank. The specimen was too young to show adult characters clearly, making the original description necessarily brief. The fish was moved to Stigmatochromis by David Eccles and Trewavas herself in their 1989 classification of Malawi haplochromines (Cichlidae, Cichlids of Lake Malawi), where they defined the genus by its distinctive melanin pattern — a small supra-pectoral spot below the upper lateral line, a supra-anal spot between the lateral lines, and a spot at the end of the caudal peduncle — and its prognathic lower jaw. Konings (2016) and Eschmeyer's Catalog of Fishes (updated May 2026) both confirm its current placement as valid within Stigmatochromis, with no synonyms beyond the original combination Haplochromis pleurospilus. GBIF backbone taxonomy records the species under key 2370045. The only other scientific treatment of any depth is Snoeks and Hanssens's 2004 identification guide chapter in The Cichlid Diversity of Lake Malawi/Nyasa/Niassa (Cichlid Press), which reported two additional specimens and compared the species' known characters with the cave-dwelling Otopharynx spelaeotes and Otopharynx antron, which superficially resemble it; that comparison was further developed by Cleaver, Konings and Stauffer (2009) in Ichthyological Exploration of Freshwaters. M.K. Oliver of malawicichlids.com photographed the holotype from both sides at the Natural History Museum and noted that the species may belong in Otopharynx on the basis of its melanin-pattern characters, cautioning that a rocky-associated genus would not be expected from a purely sandy habitat — a reservation that has not yet prompted a formal revision. The current, widely accepted assignment remains Stigmatochromis.
No trade name exists, and FishBase records no common name. The species is absent from the aquarium trade under this name; fish occasionally sold as 'Stigmatochromis pleurospilus' in Australia appear to be correctly identified individuals kept by a very small circle of specialists.
Morphology
The holotype — the only specimen measured in Trewavas's original description — is an immature fish of 1.5 in SL, and the two Snoeks and Hanssens specimens are described as 'nearly adult but no more than 3.5 in standard length,' giving a total scientific size range of 1.5–3.5 in SL. The IUCN assessment (Konings 2018) records the largest of the three known scientific specimens at 4.5 in total length. FishBase records a maximum of 3.5 in SL for the species (from Ref. 55954), consistent with the Snoeks and Hanssens material. Hobbyist sources, notably a detailed post on the Australian Cichlid Enthusiasts Forum (2015) by a keeper who bred the species, report aquarium fish reaching approximately 10 in; this figure is unverified in the scientific literature and should be treated with caution — it may reflect incorrectly identified specimens, or the genus's full adult potential in the absence of predation and competition. Until a series of adult wild fish is examined, the true maximum size remains uncertain.
In body shape Stigmatochromis pleurospilus is a fusiform haplochromine with a torpedo-like, laterally somewhat compressed body — a form consistent with an active, open-water predatory lifestyle over sandy substrates. The defining genus characters are the three-spot melanin pattern (small supra-pectoral blotch below the upper lateral line; supra-anal blotch between the lateral lines; precaudal blotch at the end of the caudal peduncle), together with a prognathic lower jaw that extends slightly forward of the premaxillary tips in adults — a feature distinguishing Stigmatochromis from the morphologically similar Otopharynx, whose snout is shorter than the post-orbital head length. In breeding males, aquarium observation reports a yellow-washed belly with pastel blue on the head and upper flanks, blue patterning on the dorsal fin with yellow spots, and a generally pale-coloured body consistent with a sand-zone fish. Females are considerably duller — brownish to silver-grey with the species' spot markings retained but subdued. Sexual dimorphism is present and pronounced in nuptial condition.
Habitat
Lake Malawi — also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique — is a deep, ancient rift lake straddling the borders of Malawi, Tanzania and Mozambique. Its surface water maintains pH ~7.7–8.6 and temperatures of roughly 75–82 °F in the upper 164 ft, with conductivity around 200–230 µS/cm. Stigmatochromis pleurospilus is known from only two confirmed localities within this lake: the type locality at Lupembe Sandbank near the north end of the lake, and Ifungu (Kirondo) on the northeastern Tanzanian shore, where Snoeks and Hanssens collected two specimens in the early 2000s. Additional fish have reportedly been observed or collected at Mdoka (northwestern Malawi shore), based on keeper and field accounts, though no voucher specimens from that site appear in the peer-reviewed literature. The IUCN range description lists the species as present in both Malawi and Tanzania.
The IUCN assessment (Konings 2018) notes that the species is 'perhaps a species from shallow sandy habitats,' which is consistent with both the type locality (a sandbank) and with the genus's broader association with open sandy or intermediate-zone biotopes. Community-level hobbyist accounts describe the natural habitat as shallow sandy bays at depths of 33–131 ft — a range that is plausible for a Stigmatochromis-grade piscivore in northern Malawi, where sandy shelves border the rocky shores. No in-situ water-chemistry measurements specific to the collection localities have been published; the pH, temperature and depth values given here are habitat-typical for northern Lake Malawi's sandy zones, inferred from the broader lake chemistry literature and flagged accordingly.
Feeding
No gut-content data or trophic analyses have been published for Stigmatochromis pleurospilus from wild specimens. The genus Stigmatochromis is characterised as piscivorous within the Lake Malawi haplochromine radiation — a trophic role reflected in the prognathic lower jaw and the torpedo-shaped body that multiple members of the genus share. FishBase assigns a modelled trophic level of approximately 3.8 for the species, placing it clearly in the predator guild. The IUCN assessment (Konings 2018) does not specify a diet, but notes the habitat as sandy wetlands consistent with open-water hunting over sand.
Community aquarium accounts describe the species as hunting small fish in sandy environments — consistent with the Stigmatochromis feeding mode in which the predator uses open sandy areas as a hunting ground, either pursuing prey actively or lying in wait using colour camouflage over pale substrate. Accepted aquarium foods include high-quality pellets and, as fish mature, live or frozen prey items such as brine shrimp and small feeder fish to maintain breeding condition. Until wild dietary evidence is published, piscivory over sandy habitats should be regarded as a well-supported inference rather than a documented fact for this particular species.
Mating
The mating system of Stigmatochromis pleurospilus in the wild has not been studied, but its placement in Stigmatochromis and aquarium observations provide a consistent picture. Males in the aquarium construct substantial bowers — circular depressions in the sand approximately 3–5 ft in diameter — which they defend as spawning territories. This bower-building behaviour is consistent with the broader haplochromine pattern in Malawi's sand-dwelling and open-water piscivores, and with observations of the related Stigmatochromis species.
Females appear to be attracted to bower-holding males. Keeper reports note that males can be moderately aggressive toward one another — somewhat less so than some other Stigmatochromis species, based on community experience — and are heavy on females, necessitating a skewed sex ratio of at least three females per male in captivity. Males apparently achieve sexual maturity at approximately eight months. The social structure over sandy habitats in the wild is presumed polygynous, with multiple males maintaining bowers across a sandy bay and females choosing among them — a pattern typical of lake haplochromines generally.
Breeding
Stigmatochromis pleurospilus is a maternal mouthbrooder, as is universal among Malawi haplochromines. The female broods fertilised eggs and larvae in her buccal cavity, providing all post-spawning parental investment; the male takes no part in brooding or fry care. Clutch size from aquarium spawnings is reported at approximately 25 fry — a modest brood consistent with the species' moderate size and the generally smaller clutches of large-egg maternal mouthbrooders compared with smaller species. No data on incubation temperature, buccal brooding duration, or fry size at release have been published from either wild or captive observation.
Breeding in captivity has been achieved; aquarium accounts describe a species that spawns willingly once a stable colony is established. A 6×2×2 ft (approximately 180×60×23.5 in) minimum tank is recommended, with a sandy substrate and adequate space for male bower-building. Sexual maturity is reportedly reached after approximately eight months. Because the male is physically demanding on females — pursuing ripe individuals persistently — multiple females per male and the ability for females to escape visual contact are essential management practices.
In the aquarium
Stigmatochromis pleurospilus is rarely kept in the hobby. Outside a very small circle of specialists — primarily in Australia, where a handful of keepers bred the species and shared observations on the ACE Forum circa 2015 — the fish is essentially absent from the trade under its correct name, and any fish labelled as such should be considered highly unusual. Prospective keepers should not expect this species to become available through conventional aquarium retail channels; acquiring it generally requires contact with the small specialist network that holds stock. That rarity, combined with the thin scientific record, means that much of what follows is generalised from Malawi haplochromine ("Hap") husbandry practice, with specific notes from keeper accounts where available.
Tank size is the first non-negotiable. Aquarium observers report fish potentially reaching around 10 in under captive conditions — unverified against wild specimens but credible for a large-bodied piscivorous Hap. A single male with two or three females will require a minimum of 180 × 60 × 23.5 in (roughly 6 × 2 × 2 ft, around 170 US gal). A deeper or wider footprint is better still, as males construct circular sand bowers up to a metre in diameter that they defend vigorously; too small a tank leaves females nowhere to retreat. The substrate should be fine to medium silica or play sand — pale sand helps males display their full nuptial colour and is consistent with the natural sandy-bay habitat. Rockwork can be added around the perimeter and ends to create visual breaks and refuge zones, but the majority of the floor area must remain open sand to allow bower-building. Filtration should be robust; a large predatory cichlid eating whole fish-based foods produces a significant waste load.
Water chemistry must match the Lake Malawi profile: pH 7.8–8.6, temperature 75–82 °F, and moderate to high alkalinity (general hardness roughly 10–20 °dH, carbonate hardness 8–16 °dH are typical targets for Malawi tanks). Regular partial water changes of 20–30 % weekly are the primary tool for keeping nitrates under control and maintaining buffering capacity. Soft or acidic water will suppress colour, stress the fish, and over time predispose them to osmotic stress and disease. Malawi bloat — a metabolic and infectious condition associated with dietary imbalance, high nitrates, and inappropriate water chemistry — is the single most common preventable cause of death in Malawi Haps in captivity and has been reported in keeper accounts of Stigmatochromis species. A species-appropriate high-protein diet (quality pellets formulated for piscivores, supplemented with meaty frozen foods) alongside consistent water quality is the core preventive strategy.
Tankmate selection is severely constrained by the species' piscivorous nature. Stigmatochromis pleurospilus will eat any fish small enough to swallow — including standard-sized mbuna, smaller Haps, and juvenile fish of any species. Only robust, comparably large Malawi haplochromines or other large Malawi cichlids should be considered as companions, and even then male-to-male aggression between territorial species can be severe in confined spaces. Mixing with mbuna is generally not recommended, both because mbuna are potential prey for a large Stigmatochromis pleurospilus and because the dietary requirements differ (mbuna are largely herbivorous; feeding mixed tanks a piscivore diet risks Malawi bloat in the mbuna component). Peaceful large Haps that share similar water requirements — such as large Copadichromis or other non-aggressive open-water species — are the safest choices for a species display tank. In practice, many keepers maintain the species as a species-only colony.
Breeding is achievable for keepers who meet the tank-size and water-quality requirements. Males reach sexual maturity at approximately eight months under aquarium conditions, at which point bower construction and display intensify. Males are demanding on females — persistently pursuing and harassing ripe individuals — so maintaining at least two or three females per male, with sufficient decor to break lines of sight, is essential to prevent female exhaustion. Spawning occurs in the bower; the female broods the eggs buccally. Reported clutch sizes are around 25 fry. The female should be allowed to hold for the full brooding period (typically 18–21 days is expected for large Malawi mouthbrooders at 77–81 °F, though no published data exist for this species specifically) before being moved to a separate tank to release the fry, or alternatively the fry can be stripped and raised separately. The difficulty of acquiring stock in the first place, rather than any unusual husbandry challenge, is the main barrier for most aquarists.
Conservation
The IUCN Red List assesses Stigmatochromis pleurospilus as Data Deficient (DD), assessed 19 June 2018 by Ad Konings and Jos Snoeks (published in the 2018-2 version). The justification is straightforward: until 2004 the species was known only from the type — a single juvenile barely 1.5 in long collected in 1925–26. When Snoeks and Hanssens located two additional sub-adult specimens at Ifungu (Kirondo) in Tanzania, the total number of scientifically documented individuals reached three. The IUCN notes that while more information is needed to assess extinction risk, the species does not appear to be targeted by the ornamental fish trade, and no specific threats are identified. A Data Deficient listing does not mean the species is not at risk; it means the data needed to evaluate that risk are absent.
Lake Malawi itself is, however, under documented and accelerating pressure. Fisheries analyses and limnological surveys — including Chavula et al. (2023) and the broader basin literature — record declining fisheries yields, deforestation-driven sedimentation that is smothering littoral and shallow sandy habitats, agricultural nutrient loading, and the effects of a warming climate on thermal stratification and productivity. Sandy-habitat specialists in the north of the lake are potentially exposed to shoreline modification and sedimentation, while the lake's small-scale commercial fishery applies diffuse pressure throughout. That the only confirmed localities for Stigmatochromis pleurospilus are in the poorly surveyed northern reaches of the lake, in both Malawi and Tanzania, means that targeted survey effort is the most urgent conservation need: the species may be more widespread than the three-specimen record suggests, or it may genuinely have an extremely limited distribution. Until that survey work is done, its true status cannot be determined, and the Data Deficient listing appropriately reflects that uncertainty.