Taxonomy & naming
Rhamphochromis sp. "Chilingali" is undescribed: no holotype, no publication, no entry in Eschmeyer's Catalog of Fishes. It belongs to Rhamphochromis, the genus of elongate, open-water, fish-eating haplochromines erected by Regan in the early twentieth-century revision of Lake Malawi's cichlid genera; the precise year of that description is not asserted with confidence here, and Eschmeyer's Catalog of Fishes is the standing authority on it. "Chilingali" is the locality tag, taken from Lake Chilingali, a small satellite lake in the Kaombe River catchment near Nkhotakota that is emphatically not part of Lake Malawi proper, though it lies within the same broader lake basin and drains toward it. This Rhamphochromis is the pelagic, piscivorous counterpart to the small sand-dwelling cichlid Lethrinops chilingali, formally described from the same lake in 2023 by Turner, Crampton and Genner; the two are treated by the describing authors and subsequent surveyors as co-endemics of the same isolated basin, stranded there — by inference from the genus's documented origin — after receding lake waters separated the Chilingali basin from the main body of Lake Malawi.
Morphology
Like other Rhamphochromis, this form is presumed to show the genus's extremely elongate, streamlined, pike-like body, tapering to a slender caudal peduncle, with a large mouth and conspicuous teeth built for pursuit predation rather than grazing or sifting. No morphological description, measurement or colour account specific to this population has been published in the sources available here. The genus's ground colour is typically silvery, sometimes with a dark horizontal flank stripe, and mature males in the better-studied Lake Malawi species such as R. esox develop brighter nuptial colour including orange fins and anal-fin egg-spots; whether this Chilingali population shared that pattern was never documented before the population apparently disappeared.
Habitat
Rhamphochromis sp. "Chilingali" is endemic to Lake Chilingali, a small satellite lake roughly 3 mi long and at most 1 mi wide, lying in the Kaombe River catchment near Nkhotakota in central Malawi and connected to Lake Malawi only intermittently via the Kaombe River, which meanders roughly 7 mi to reach the main lake. This is a fraction of the scale of the open, pelagic Lake Malawi habitat that the rest of the genus occupies, so "open water" here means the small lake's own limited pelagic zone rather than the vast offshore expanse used by species such as R. esox or R. woodi. The lake's recent history has been turbulent: a dam built across its single outflow around 1992 raised the water level and merged two historically separate basins, the dam later collapsed and the lake largely drained to about a metre deep by 2016, and a new dam refilled it in 2019. Water in the lake was highly turbid whenever it was visited between 2004 and 2009, so this fish's behaviour in its home lake was never directly observed even before it apparently vanished.
Feeding
Rhamphochromis as a genus are the principal open-water piscivores of Lake Malawi, hunting small shoaling fish with a streamlined body and toothy jaws built for pursuit rather than ambush. In the confined waters of Lake Chilingali, this population's prey base would necessarily have been limited to whatever small fish and invertebrates the tiny lake supported, very plausibly including young Lethrinops chilingali and the phantom-midge (Chaoborus) larvae documented as a major food item for that co-endemic species. No feeding study specific to this Rhamphochromis population has been published, so this account is inference from the genus's well-documented ecology in the main lake rather than direct observation here.
Mating
Rhamphochromis in the main lake are schooling, open-water fish with no sharply defined breeding season and males that develop brighter nuptial colour to attract mates rather than forming exclusive pairs. Whether that pattern held in the confined, turbid waters of Lake Chilingali — where schooling space and visibility would both have been far more limited than in the open lake — was never documented, and no behavioural account of this specific population exists.
Breeding
Like the rest of its genus, Rhamphochromis sp. "Chilingali" is presumed to have been a maternal mouthbrooder, with the female taking fertilised eggs into her buccal cavity and brooding them for several weeks before releasing free-swimming fry with no paternal care. No clutch size, brooding duration or other reproductive data specific to this population was ever documented before it apparently disappeared from the wild.
In the aquarium
Rhamphochromis sp. "Chilingali" has essentially no presence in the aquarium hobby. Rhamphochromis as a genus reach aquarists only sporadically even from the main lake, and this satellite-lake population — confined to a single small, remote and periodically drained lake, and now presumed extinct in the wild — was never established in the ornamental trade or, as far as is documented here, in any captive conservation programme of the kind that preserved its co-endemic Lethrinops chilingali. There is, at present, no known living population of this fish anywhere.
Conservation
Rhamphochromis sp. "Chilingali" has no formal IUCN Red List assessment, and as an undescribed taxon it cannot receive one under current nomenclatural rules — but the informal picture here is genuinely urgent rather than merely unevaluated. Lake Chilingali's single outflow dam collapsed sometime before 2016, draining the lake to roughly a metre deep and devastating its small, isolated fish fauna; a new dam refilled the lake in 2019. When George Turner and colleagues described the co-endemic Lethrinops chilingali in 2023, they recommended it be considered Extinct in the Wild, since it had not been recorded since 2009. A field survey in 2024, led by Turner with Chester Zoo and Malawian partners, found Lethrinops chilingali rediscovered and abundant in the refilled lake and the wider Kaombe catchment — but did not find this Rhamphochromis at all. It is accordingly presumed extinct in the wild, with no known captive population as insurance. Whatever combination of habitat collapse, introduced tilapia during restocking and the basin's inherently tiny population size drove that outcome, the case stands as a stark illustration of how fragile isolated satellite-lake faunas are, and how differently two co-endemic species sharing the same small lake can fare through the same crisis.