Taxonomy & naming
Charles Tate Regan described this fish in 1922 as Haplochromis spilorhynchus, in his monograph "The Cichlid Fishes of Lake Nyassa" published in the Proceedings of the Zoological Society of London (1921, part 4, no. 36, pp. 675–727). The primary type material consisted of several specimens in the Natural History Museum, London; Eccles and Trewavas (1989) later designated BMNH 1921.9.6.181 as lectotype and BMNH 1921.9.6.182–184 as paralectotypes. The type locality is Lake Malawi (then Lake Nyasa), southeastern Africa — no more precise collection point was recorded in the original description. In the same 1922 paper Regan also described Haplochromis longipes from a specimen now housed as BMNH 1921.9.6.185; that fish, a sexually active male with elongated pelvic fins, was subsequently synonymised with spilorhynchus by Trewavas (1935), the elongated rays being dimorphic expression in breeding males rather than a species-diagnostic trait. The genus Champsochromis was erected by Boulenger in 1915, and the current combination Champsochromis spilorhynchus (Regan, 1922) has been stable since Eccles and Trewavas's authoritative 1989 revision of Malawi haplochromines; it is accepted by Eschmeyer's Catalog of Fishes, FishBase, GBIF, and the IUCN. The genus holds two species: the present fish and Champsochromis caeruleus, the more familiar "Malawi trout." Both sit in the tribe Haplochromini within the vast subfamily Pseudocrenilabrinae, the core of Lake Malawi's explosive cichlid radiation. In the aquarium trade the species has circulated under the unofficial label "Haplochromis Mbwanae," a name with no scientific standing; local Malawian names recorded by Jackson (1961) include Tabwa, Damphila (or Dumphila), and Njeruwa. Aquarists have also long lumped it into an informal trade grouping, "Haplochromis Torpedo" — mixed importer shipments of slender, diagonally-striped haplochromines sold together under one label and needing careful sorting by eye, a group that has historically included Sciaenochromis gracilis, Sciaenochromis spilostichus, an undescribed Stigmatochromis sp. "Spilostichus Type," and Champsochromis caeruleus alongside spilorhynchus itself.
Morphology
Champsochromis spilorhynchus is a large, elongate, fusiform cichlid — streamlined for sustained open-water pursuit rather than the tight maneuvering of a reef-dwelling mbuna. FishBase lists a maximum total length of 12 in for unsexed specimens, while Ad Konings (1995c), the foremost observer of these fish in their natural habitat, gives a maximum total length exceeding 14 in; captive and field accounts suggest the larger figure is more representative of adult males. Compared with its only congener, Champsochromis caeruleus, it is more deep-bodied: Eccles and Trewavas (1989) give greatest body depth going 3.2–3.6 times into the standard length in spilorhynchus versus 3.8–4.6 times in the more slender caeruleus — a difference visible in the field and in aquarium photographs, though the two species otherwise share a similar habitus.
The most distinctive external feature is the preorbital mark: a large, sharply defined black blotch on the lacrimal (lachrymal) bone, extending from just in front of the eye to the upper jaw, which is the name-giving character. This mark is present in both sexes and at all ages, though it may appear somewhat less contrasting in large adults with overall darker ground coloration. The body carries a dark, obliquely running lateral stripe, and the outer jaw teeth are unicuspid and widely spaced — a shared character with Champsochromis caeruleus that reflects the piscivore guild. Sexual dimorphism exists but is less pronounced than in caeruleus: dominant males can develop elongated soft rays on the dorsal and anal fins, though not quite to the dramatic trailing-filament degree seen in large male caeruleus; females are plainer, without elongated fins or strong iridescent colour.
Habitat
Champsochromis spilorhynchus is a lacustrine endemic, its range encompassing Lake Malawi, the connected Lake Malombe to the south, and the upper Shire River draining from Malombe — wherever the habitat holds water deep and open enough for a coursing predator. Because Malawi's shoreline spans three nations, its range falls within the waters of Malawi, Mozambique, and Tanzania. Eccles and Trewavas (1989) describe the distribution as "inshore all around the lake and in the upper Shire River, but also extends well offshore." The IUCN assessment notes that larger individuals are encountered down to roughly 66 ft depth, while juveniles and sub-adults occupy shallower water, including vegetated beds in water only a metre or two deep — precisely the habitat devastated by beach-seine operations.
The species shows no strong affinity for rocky substrates. Its primary biotope is over sand and muddy bottoms, the open, mid-water zones above these substrates, and intermediate (sand-rock transition) areas — wherever its shoaling prey congregates. Ad Konings' own habitat classification in Enjoying Cichlids places it among the piscivores of muddy bays specifically, reinforcing that this is a soft-bottom fish rather than a rocky-shore one. The water chemistry it inhabits is the classic Malawi profile: hard, well-buffered, and alkaline. FishBase records in-situ temperatures of 75–79 °F; the lake's surface layer spans approximately 75–82 °F across the year, with pH values of roughly 7.7–8.6 and alkalinity buffered by the lake's deep carbonate-rich sediments. As a wide-ranging pelagic predator its precise distribution is tied less to substrate than to the movements of its prey.
Feeding
Champsochromis spilorhynchus is a dedicated pursuit piscivore — a fish that runs down smaller fish in open water rather than ambushing them from cover or cropping the bottom. FishBase assigns it a trophic level of 4.2, the same as its congener Champsochromis caeruleus, placing it near the top of the lake's food web. Ad Konings (1995c) describes it as "a formidable piscivore following its prey over long distances (rather than ambushing it)," and identifies young utaka — the Copadichromis species that form dense mid-water shoals around Malawi's rocky reefs and sandy shorelines — as its primary prey. M. K. Oliver (malawicichlids.com) also cites young utaka as the chief diet, and notes that the large, conical, well-spaced outer teeth are suited to seizing slippery prey fish rather than scraping algae or crushing molluscs.
In the wider ecology of Lake Malawi, Champsochromis spilorhynchus occupies the same functional niche as Champsochromis caeruleus: mobile top-end fish predators that crop the lake's enormous biomass of small haplochromines and schooling cyprinids. The two species divide their ecological space imperfectly — spilorhynchus is on average the heavier-bodied fish and may tend toward slightly shallower, more inshore hunting grounds — but detailed trophic partitioning studies of the two congeners in the wild are lacking. Both are vulnerable to the collapse of the prey base that deeper stratification and overfishing of the lake's small-pelagic fauna represent.
Mating
Outside the breeding season Champsochromis spilorhynchus is a largely solitary, wide-ranging predator; juveniles sometimes gather loosely in shallow plant-bed areas, but adults are uncommonly sighted even by experienced divers who have logged hundreds of hours in the lake. The IUCN assessment by Ad Konings notes that in hundreds of hours of diving only a few juveniles have been observed in very shallow plant beds — a measure both of the species' current rarity and of the difficulty of observing adults in open water.
The pre-spawning and mating behaviour of Champsochromis spilorhynchus has not been documented in the detail available for its congener. Given the close phylogenetic affinity between the two Champsochromis species and the overall uniformity of mouthbrooder spawning rituals among Malawi haplochromines, the courtship sequence is expected to follow the standard pattern: a ripe male establishing and defending a spawning site over sandy substrate, intensifying in colour to attract females, and the pair descending together to the spawning surface. Fertilisation takes place inside the female's mouth in the manner typical for all Malawi haplochromines. Hobbyist accounts (cichlid-forum.com) note that a dominant male in the aquarium turns "deep blue almost purple with a splash of red" when active, while a non-displaying male may show the lateral stripe as the dominant pattern — consistent with the dichromatism seen across the haplochromine haps.
Breeding
Like all Malawi haplochromines, Champsochromis spilorhynchus is a maternal mouthbrooder: the female collects the eggs into her mouth immediately after spawning, where they are fertilised and where the developing embryos and larvae are incubated until the young are free-swimming. FishBase (ref. 2060, Konings 1990) records that the female carries over 100 young in her mouth, suggesting a brood size that is larger than in Champsochromis caeruleus, which typically produces only 30–35 large-yolked eggs. The difference likely reflects the slightly different body size at maturity and the smaller individual egg size implied by the higher count. The Cichlid Room Companion entry by Konings records fish from Mvunguti brought back by an expedition with Stuart Grant's fishermen, and notes that an aquarium strain produced from this wild-caught material should be "carefully preserved, given the rarity of this species in the natural environment."
In captivity, Champsochromis spilorhynchus is exceptionally rare: the IUCN-documented population collapse means that very few individuals enter the ornamental trade, and those that do tend to be the product of the small dedicated European captive-breeding programmes rather than fresh imports. The species is no longer being actively targeted by Malawi fish exporters. For the hobbyist fortunate enough to work with it, the practical requirements mirror those for Champsochromis caeruleus: a very large tank (at least 1,0.5 US gal is the figure cited by M. K. Oliver), stable Malawi-typical water chemistry, a long footprint to allow full-speed swimming, and prey-sized tankmates to be avoided. Aggression to conspecifics is significant.
In the aquarium
Champsochromis spilorhynchus is one of the largest and most demanding cichlids from Lake Malawi, and any honest assessment of its aquarium requirements begins with size. An adult male can exceed 14 in in total length and is a continuously active, open-water cruiser — not an ambush predator content to wedge itself into a cave. The minimum footprint generally cited in the specialist literature for large open-water Malawi haplochromines of this size is around 94.5 in in length; for Champsochromis spilorhynchus specifically, M. K. Oliver (MalawiCichlids.com) recommends at least 1,0.5 US gal, and this figure is a sensible baseline rather than a generous suggestion. The tank should be oriented for maximum swimming distance — long and wide, not tall. Elaborate rock decor is out of place and wastes the open volume this fish needs; a fine-sand substrate (0.5–1 in, white or light tan to approximate the sandy bottoms of the lake) with perhaps one or two large inert rock formations toward the rear or ends of the tank is appropriate. Robust, deep-rooted plants are likely to be uprooted or ignored; the species has no ecological relationship with vegetation and the biotope does not call for it.
Water chemistry must reflect the Lake Malawi source. The lake maintains a pH of roughly 7.7–8.6, temperatures of 75–82 °F, and is hard and well-buffered by deep carbonate sediments; none of these parameters should be compromised. Soft, acidic, or low-alkalinity water will stress the fish and suppress immune function over time. Target pH 7.8–8.5, carbonate hardness above 10 dKH, general hardness in the 15–25 dGH range, and temperature 77–81 °F for routine maintenance. Strong, efficient filtration is essential — a large piscivore with a high protein diet produces a corresponding waste load. Turnover of at least 8–10 times the tank volume per hour, split across multiple outlets to avoid strong localised flow, is a reasonable starting point.
Tankmate selection is severely constrained by two factors: the fish's size and its diet. Champsochromis spilorhynchus is a pursuit piscivore built to run down and swallow Copadichromis-sized cichlids in open water; any fish small enough to fit in its mouth will eventually be eaten, and many fish that are technically too large will still be harassed or injured. Suitable companions are limited to other robust, large Malawi haplochromines of comparable size — big Nimbochromis, large Tyrannochromis, or similar-scale open-water haps that are not small enough to be prey — and even then territorial disputes in a confined space are possible. Mbuna (the rock-dwelling Malawi cichlids such as Pseudotropheus, Labidochromis, and Melanochromis) are entirely unsuitable: they occupy a different niche, experience chronic stress in open tanks, and are prey-sized to a large spilorhynchus. This is fundamentally a species for a species-focused or near-species setup rather than a community Malawi display, and a single male with two or three females is the most manageable arrangement.
Breeding in captivity is rare given the extreme scarcity of the fish in trade, but the mechanics follow the standard Malawi mouthbrooder pattern. A ripe male intensifies to deep blue-purple with a red flush and courts females over a prepared sandy spawning site; the female takes the eggs into her mouth immediately after laying, fertilisation occurs in the buccal cavity, and she carries the developing young for approximately three weeks at normal Malawi temperatures. Broods appear to be large — FishBase records more than 100 young per clutch (citing Konings 1990), which is notably higher than the 30–35 eggs typical of Champsochromis caeruleus. A ripe female should be moved to a separate holding tank to allow her to carry undisturbed, since a male this large can injure a brooding female that fails to respond to renewed courtship. The fry are released at a relatively advanced free-swimming stage and will accept Artemia nauplii and finely crushed cichlid pellet from the outset.
The species' overall difficulty rating is high, and not primarily because of water-chemistry complexity — standard Malawi conditions are well understood. The difficulty lies in the scale of the infrastructure required, the near-total absence of the fish from current trade, the aggressive and predatory nature of adults, and the specialist feeding regime (meaty, high-protein foods; live or frozen fish, large earthworms, and quality carnivore-formulated pellets form the practical diet in captivity). Newcomers to Malawi cichlids should work with smaller, more forgiving species first. For the advanced keeper with the space and dedication, however, Champsochromis spilorhynchus is among the most ecologically and visually distinctive haplochromines in the lake, and maintaining a captive population contributes in a small way to the preservation of a species whose wild numbers are genuinely alarming.
Conservation
The IUCN Red List currently lists Champsochromis spilorhynchus as Endangered (EN, criterion A2ad), assessed on 22 May 2018 by Ad Konings, who based the evaluation on direct underwater survey data accumulated over decades of diving in Lake Malawi. The assessment is stark: a species that was common in the early 1980s has undergone a population-size reduction estimated at greater than 90 percent by the mid-1990s, and was not recorded at all during a 2016 survey of the southern part of the lake. In hundreds of hours of in-water observation since the late 1990s, Konings noted only scattered juveniles in shallow plant beds. The previous (2006) assessment had rated it Least Concern — the dramatic reversal in status reflects both the depth of the collapse and the value of long-term in-situ expertise over coarse distribution data. No CITES listing applies.
The proximate cause is beach-seine fishing. Subsistence and small-scale commercial seines swept around the shallow margins of the lake target the shallow, vegetated areas that juvenile and sub-adult Champsochromis spilorhynchus occupy. Unlike the offshore-cruising adult Champsochromis caeruleus, whose deeper habits and lower beach-seine vulnerability may have buffered it from a similar collapse, spilorhynchus appears to depend on the inshore shallows during its formative years — exactly the zone that bears the heaviest fishing pressure. The species has been recorded within the Lake Malawi National Park, which in principle affords some protection, and it is no longer commercially targeted for the ornamental trade; but as long as the broader fishery regime remains unregulated in most parts of the shoreline, population recovery is unlikely.
The wider basin context frames the risk. The 2023 review by Chavula and colleagues in the Journal of Great Lakes Research documents a lake under compounding pressure: overfishing of the chambo (Oreochromis) and usipa (Engraulicypris sardella) fisheries, heavy sedimentation and nutrient loading from deforested catchments, and warming of about 33 °F in the shallow layer since the 1990s that has strengthened stratification and suppressed the deep-water nutrient upwelling underpinning lake productivity. For a top predator dependent on dense shoals of small cichlids and cyprinids, the degradation of the prey base compounds the direct mortality from bycatch. The species' IUCN estimate of area of occupancy at just 3,93 mi² — a small fraction of the lake's surface — reflects how severely its usable habitat has contracted.