Taxonomy & naming
Lugubria rosemariae was described by the Swedish ichthyologist Sven O. Kullander in 1997, in Ichthyological Explorations of Freshwaters (volume 7, pages 279-281), under the title 'Lugubria rosemariae, a new species of pike cichlid (Teleostei, Cichlidae) from the upper Rio Xingu drainage, Brazil.' The type locality is given as Córrego do Gato, in the Rio Xingu drainage of Pará, Brazil — a small headwater affluent in the vast upper-Xingu system that also feeds the Suiá-Missú River (FishBase records the broader locality as the Suiá-Missú drainage). The species has a tangled nomenclatural backstory: the Dutch ichthyologist Alex Ploeg, in his 1991 revision of the genus, had examined the relevant material and treated these fish within the widespread Crenicichla johanna, so Kullander's 1997 paper effectively recognised and named a distinct species that earlier workers had folded into a larger one. Within the genus it belongs to the lugubris species group — the assemblage of big, robust, deep-water pikes that includes Crenicichla lugubris, Crenicichla johanna and Crenicichla marmorata. In the major 2023 revision of pike-cichlid classification by Varella, Kullander, Menezes, Oliveira and López-Fernández (Zoological Journal of the Linnean Society), the lugubris-group species were split off into a resurrected genus Lugubria, so the fish now appears in current databases as Lugubria rosemariae; because the change is recent and the great majority of hobby and aquarium-trade references still use the original binomial, we keep it here under Crenicichla. The epithet honours Dr Rosemary Helen Lowe-McConnell.
Morphology
This is a large pike cichlid with the elongate, cylindrical, big-mouthed build typical of the lugubris group — a body engineered for ambush predation. The original description was based on material to about 9.5 in in standard length (FishBase lists this as the maximum recorded length), and aquarists generally cite a size of roughly 12 in (around 12 inches) total length for grown fish, making it a genuinely substantial cichlid. Its outstanding feature is colour, and specifically the fact that the sexes look strikingly different — an unusual trait among the large pikes, most of which are only weakly dimorphic. Mature males are the showpiece: a dark olive-to-bronze ground colour overlaid with numerous bright red to scarlet spots scattered across the flanks and unpaired fins, a pattern that has earned the fish a near-legendary reputation in the hobby. Females lack the red spotting entirely; they are olive, often with faint traces of vertical barring, and carry warm colour where the male carries spots — an orange iris, a deep orange cheek, and a salmon-to-orange chest. This clear sexual dichromatism is, by hobbyist accounts, unique within the lugubris group and is the most reliable way to sex the species. As in other pikes, the body bears the genus's fine scalation and a long-based dorsal fin running most of the length of the back.
Habitat
Lugubria rosemariae is endemic to the upper Xingu drainage in central Brazil — a clearwater system that rises on the crystalline Brazilian Shield and drains north through Mato Grosso and Pará before joining the Amazon. The Xingu is the fourth-largest basin in the Amazon system and one of its great clearwater rivers, and rosemariae is one of its many narrow-range endemics. Unlike the rheophilic dwarf pikes (and the Teleocichla) that specialise on the oxygen-rich rapids of the lower and middle Xingu, this species is a fish of calmer, deeper water: the type specimens were taken from a large, very clear pool stocked with large rooted macrophytes, and FishBase notes that large individuals are observed near the bottom of such pools. Co-occurring cichlids in these lentic, weed-grown habitats reportedly include eartheaters and the festive-type cichlid Mesonauta. The water is warm, soft, clear and near-neutral, characteristic of upper-Xingu shield streams and their pools; precise in-situ chemistry for the type pool was not published, so the figures used here follow the well-documented upper-Xingu envelope rather than direct readings from a rosemariae site. The shallow band given reflects the depth at which the fish are seen in these pools rather than a measured maximum.
Feeding
Like all pike cichlids, Lugubria rosemariae is a carnivore built around ambush predation — a large, protrusible, well-toothed mouth set on an elongate body that lets it lie still among plants or near the bottom and then lunge. FishBase places its estimated trophic level high, around 3.8, consistent with a diet dominated by other fishes and large invertebrates. No detailed gut-content study of this particular species has been published, so the specifics of its wild prey are inferred from its body plan, its size, and the feeding habits of its close relatives in the lugubris group, which take fish, shrimp, large insects and other sizeable live prey. Tellingly, the holotype was caught on hook and line, baited and worked by a local fisherman — direct evidence of a predator that strikes at moving, mouth-sized targets. In its community it functions as one of the larger piscivores of the quiet, plant-rich pools it inhabits.
Mating
Specific courtship and pair-formation behaviour has not been documented in the wild for Lugubria rosemariae, so what follows is read across from the genus and from hobbyist experience with the large pikes. Pike cichlids are monogamous and form lasting pair bonds, and the conspicuous male nuptial colour of this species — the rows of red spots that the female lacks — is exactly the kind of signal used in courtship and male display. Pairs are strongly territorial around the spawning site and become markedly more aggressive as breeding approaches. Among large pikes, pair compatibility is notoriously hit-or-miss: keepers report that two fish either bond quickly and stay devoted for months, or remain incompatible and dangerous to one another, and a common technique for diffusing the intense intraspecific aggression of the lugubris-group pikes is the use of 'target' fish on which a forming pair can vent hostility while their bond cements. Given its size and temperament, rosemariae should be assumed to follow this demanding pattern.
Breeding
Lugubria rosemariae has not, on the available record, been bred in captivity, and its reproduction has not been described in the wild — a reflection of how rarely the fish has reached aquarists. Its breeding biology is therefore inferred from the genus, which is highly consistent in this regard: pike cichlids are biparental substrate and cave spawners. Eggs are laid on a sheltered surface — the roof or wall of a cave, a crevice, an overhang or among heavy cover — and both parents guard the clutch and the resulting fry, with the female typically tending the eggs while the male patrols and defends the wider territory. Free-swimming fry are shepherded as a school and defended vigorously. No clutch count exists for rosemariae specifically; large lugubris-group pikes are substantial fish that lay correspondingly large clutches, so a figure on the order of several hundred eggs is a reasonable genus-typical estimate (presented as an estimate, not a measured value). Spawning in related pikes is keyed to good condition on a rich live-food diet and, often, to water changes simulating seasonal rains.
In the aquarium
Lugubria rosemariae is an advanced hobbyist's fish and has only ever trickled into the trade as an occasional, expensive import — for years it was known mostly from a single set of photographs, and even experienced pike keepers describe passing up drab juveniles (it imports as a plain, mud-brown 8 in fish) only to regret it once the adult colour came in. It has not, as far as the published record shows, been bred in aquaria. Anyone keeping it should treat it as a large, predatory, territorial pike. Tank size must be generous: a single grown adult of around 12 in needs a long tank on the order of 71 in (roughly six feet) or more, and a pair or any attempt at breeding needs more still, with sightline breaks and retreats so the fish can avoid one another. Décor should follow its biotope — open swimming space over a soft bottom, robust rooted or potted plants and submerged wood for cover, and at least one defendable cave or overhang. Water should be warm, soft and clear with a near-neutral pH: roughly 26-30 degrees C and pH about 6.0-7.5 suit the upper-Xingu origin, with strong filtration and excellent water quality, but gentle to moderate flow rather than the heavy current a true rapids pike would want. Feed it as the piscivore it is — quality frozen and live foods such as whole fish (use feeders sparingly and from clean sources), large invertebrates, shrimp and earthworms, with many specimens eventually weaning onto large sinking carnivore pellets. Tankmates must be too large to be eaten and robust enough not to be bullied; the worst mistake is housing it with anything mouth-sized or with a poorly matched conspecific, since intraspecific aggression among large pikes can turn lethal quickly. This is a fish to keep for its presence and colour, not a community animal.
Conservation
The IUCN Red List assesses Lugubria rosemariae as Least Concern, assessed on 7 November 2018 by the Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), with the population trend listed as unknown (the Cichlid Room Companion's species page, reflecting an older snapshot, still notes it as not evaluated). There is no CITES or CMS listing, and the species is of no fisheries interest. The Least Concern rating reflects the species' presence across the upper Xingu drainage rather than evidence of a large, secure population — it remains a comparatively poorly known, narrow-range Shield endemic. The broader concern is the state of its watershed: the headwaters of the Xingu basin have suffered some of the highest deforestation rates in Brazil over recent decades, and the upper basin is increasingly fragmented by stream and river damming, farm ponds, soil compaction and altered water yields, while the Xingu as a whole carries the heavy footprint of the Belo Monte hydroelectric complex downstream. None of these pressures is documented as a specific threat to this particular pike, but they are the backdrop against which a clearwater endemic of the upper Xingu's pools should be viewed.