Taxonomy & naming
Cichla cataractae was described in 2020 by Mark H. Sabaj, Hernán López-Fernández, Jonathan W. Armbruster's collaborator group — formally Sabaj, López-Fernández, Willis, Hemraj, Taphorn and Winemiller — in the Proceedings of the Academy of Natural Sciences of Philadelphia (volume 167). The species had hidden in plain sight: for generations the peacock bass of the Essequibo were lumped under Cichla ocellaris, the genus's type species and the first peacock bass ever named (Bloch & Schneider, 1801). The genus Cichla had been a taxonomic tangle for two centuries, with essentially every peacock bass filed under ocellaris until Kullander and Ferreira's 2006 review split it into fifteen species. The 2020 work added a sixteenth by separating the Essequibo's rapids-dwelling form from the lentic ocellaris it had been confused with. The two are sympatric — they occur in the same rivers — but partition the habitat, and a molecular analysis recovered cataractae not as ocellaris's sister but as a distinct lineage in a clade containing Cichla temensis, Cichla melaniae, Cichla mirianae, Cichla piquiti and Cichla pinima. The holotype, an adult female of 12 in standard length (CSBD F 3613), was taken from rocky shoals in the Rupununi River. The genus name derives from the Greek kichle, a wrasse; the epithet cataractae is Latin for 'waterfall' or 'rapids,' treated as a noun in apposition — a direct nod to the white-water habitat that sets the species apart. The Catalog of Fishes lists it as valid.
Morphology
Cichla cataractae is a stout, elongate, laterally compressed peacock bass built on the genus's standard predatory plan: a large mouth, a long body and the powerful caudal fin of a fish that must hold and manoeuvre in current. The maximum recorded size is about 15 in standard length (FishBase), with the type series including specimens to nearly 14.5 in SL; like other Cichla it can be expected to grow somewhat larger in good conditions, and breeding males develop a pronounced nuchal hump on the forehead. The colour pattern shifts dramatically with age, and it is the chief field mark separating cataractae from the sympatric Cichla ocellaris. Juveniles up to about 6 in SL carry three conspicuous dark blotches along the flank, the one beneath the soft dorsal fin largest and drawn out posteriorly into a long teardrop, distinctly separated from an elliptical blotch at the caudal-fin base; in the largest juveniles these blotches gain pale borders and become ocellated. Adults reduce this to two distinct dark blotches on the sides, each typically ocellated, together with the ocellated spot at the tail base that the genus name ocellaris immortalised. Breeding males flush with bright colour and a vivid red eye. As with all peacock bass, the dorsal fin is long and notched between its spiny and soft portions.
Habitat
Cichla cataractae is endemic to the Essequibo Basin of Guyana, where it is strongly tied to flowing water. It is known from the main Essequibo channel and its major left-bank (western) tributaries draining the Guiana Shield uplands — the Cuyuní, Mazaruni, Burro Burro and Rupununi — and the Essequibo headwaters reach into Venezuela, so the basin straddles the border. The defining ecological feature is its affinity for rocky shoals in flowing channels of clear to mildly turbid rivers; this preference for water running over rock is exactly what the name cataractae records. That sets it apart from Cichla ocellaris, which shares the same rivers but favours lentic, slow or still habitats — ponds, lagoons and backwaters. In Guyana the two are distinguished in everyday speech: cataractae is the 'falls lukunani' and ocellaris the 'pond lukunani.' FishBase classes the species as a benthopelagic tropical freshwater fish. The whole of its range falls within the Guiana-Shield freshwater province, a region of ancient rock, clear and tannin-stained rivers, and a high degree of fish endemism.
Feeding
Like all peacock bass, Cichla cataractae is a diurnal, sight-hunting predator near the top of its food web — FishBase places it at a trophic level around 4.2, the apex-predator end of the scale. The genus is dominated by piscivores that ambush and chase smaller fishes, and a rapids-dwelling Cichla is well placed to take prey swept along in or sheltering around the rocky shoals it patrols; large invertebrates such as shrimps round out the diet, especially in younger fish. The big terminal mouth, the muscular body and the powerful tail are the equipment of a fish that accelerates hard to seize prey, and the habit of holding among rocks in current lets it intercept fish moving through the channels. As an apex predator restricted to fast, rocky stretches, it occupies an ecological niche distinct from that of its lentic congener, which reduces direct competition between the two peacock bass that share these rivers.
Mating
Direct breeding observations specific to Cichla cataractae are not detailed in the original description, but the reproductive biology of the genus is well documented and consistent across species. Peacock bass are pair-bonding, biparental substrate spawners. A male and female form a pair, and the male develops the characteristic nuchal hump on the forehead and intensifies in colour — in cataractae, the breeding male shows the bright red eye figured in the type series. The pair selects and cleans a firm spawning surface, typically a flat rock or other hard substrate, and defends a territory around it; in a rocky, flowing-channel habitat, suitable hard surfaces are abundant. Courtship follows the usual cichlid sequence of lateral displays, fin-spreading and substrate-cleaning passes before the eggs are laid. The heightened coloration of both fish at this time is part of the pair's signalling and territorial advertisement.
Breeding
On the genus-typical pattern, Cichla cataractae is an open, biparental substrate spawner with extended parental care. The adhesive eggs are laid in rows on a cleaned hard surface and guarded by both parents; peacock bass are notably attentive, fanning and defending the clutch through hatching. After hatching the wrigglers are moved to pits, and once free-swimming the fry form a dense school herded and guarded by both adults — a conspicuous behaviour in the genus, where parents shepherd large broods of young through the shallows for an extended period. Cichla clutches are large, often numbering in the thousands of eggs in the bigger species, though no clutch count is separately published for cataractae, which is a relatively modest-sized peacock bass. The combination of a hard-surface spawn, a guarded larval pit and a parentally herded fry school is the standard Cichla reproductive strategy; nothing in the original description suggests cataractae departs from it, beyond doing it in clearer, faster, rockier water than most of its relatives.
In the aquarium
Cichla cataractae is, first and foremost, a wild Guiana-Shield species described only in 2020, and it is not an established aquarium fish; what guidance exists is extrapolated from the genus, which has a long history in the hobby among keepers of large predators. Any peacock bass is a big-tank proposition. Even though cataractae is one of the smaller Cichla at under 15.5 in, an adult needs a long tank measured in hundreds of litres, with powerful filtration to cope with a messy piscivore's waste load and the strong, well-oxygenated flow this particular species would experience in its native rapids — of all the peacock bass, the rapids-dweller is the one most likely to appreciate brisk current and high dissolved oxygen.
Water should track the clear, warm, soft and slightly acidic-to-neutral rivers of the Guiana Shield: tropical temperatures and soft, low-conductivity water suit it, with the usual large, regular water changes that a heavily fed predator demands. Décor of smooth rocks and a few sturdy roots over open swimming space echoes the rocky-shoal habitat and gives a pair potential spawning surfaces. Feeding is straightforward for a piscivore — appropriately sized meaty foods, working captive-raised fish toward prepared and frozen items rather than relying on feeder fish, which carry disease risk. Tankmates must be robust and too large to be swallowed; anything that fits in the mouth is food. This is a fish for an experienced keeper with the space and filtration to do it properly, not a community cichlid, and given its recent description and limited availability it remains far more a fish of the river than of the aquarium.
Conservation
The IUCN Red List assesses Cichla cataractae as Least Concern (assessed 29 May 2023). Although it is a single-basin endemic, the Essequibo and its Guiana-Shield tributaries form a large, relatively intact drainage, and the species is distributed across the main channel and several major tributaries rather than confined to one short reach, which buffers it against localised disturbance. It carries no CITES listing. The general pressures on Guiana-Shield freshwaters apply as a backdrop — deforestation and sedimentation, and especially alluvial gold-mining with its associated mercury contamination and increased turbidity, which is a particular concern for a clear-water, rapids-dwelling fish — but none is documented as a population-level threat to this species at present. Because cataractae was only separated from Cichla ocellaris in 2020, older records and any fishery or trade figures that predate the split conflate the two, so its true status is best read through the lens of habitat condition in the Essequibo rather than through historical catch data.