Taxonomy & naming
Apistogramma ortegai was described in 2014 by Ricardo Britzke, Claudio Oliveira and Sven O. Kullander in the journal Zootaxa (vol. 3869, no. 4, pp. 409–419). The holotype — an adult male of 1.5 in standard length (MUSM 48898, in the fish collection of the Museo de Historia Natural in Lima) — was taken on 13 August 2011 from a small forest quebrada, or stream, tributary to the Ampiyacu River near the town of Pebas in Departamento Loreto, Peru, at roughly 3°19'S, 71°51'W. Paratypes from the same collection are divided among the Lima museum, the Swedish Museum of Natural History (NRM) and the Laboratório de Biologia e Genética de Peixes (LBP) in Botucatu, Brazil. The genus Apistogramma was erected by Charles Tate Regan in 1913, its name joining the Greek apistos, 'inconstant' or 'uncertain', with gramme, 'line' — a nod to the interrupted, often incomplete lateral line of these small fish. The specific epithet honours Professor Hernán Ortega Torres, ichthyologist and collection curator at the Universidad Nacional Mayor de San Marcos in Lima, for a career spent on the fishes of Peru. Britzke and colleagues placed the species in the Apistogramma regani group, which shares with Apistogramma commbrae, Apistogramma inconspicua and Apistogramma linkei a diagnostic tail mark where the caudal spot runs forward into the seventh body bar. Notably, the describers folded two long-known aquarium forms into the new species: the bright-blue 'Pebas' fish and the multicoloured 'Papagei' (also written 'Papagey' or 'Papagai'), both figured by Koslowski in his 2002 Apistogramma handbook as undescribed Apistogramma sp. That synonymy is not universally accepted. Specialists — notably Mike Wise and the German biologist Uwe Römer, working partly from unpublished DNA — argue that the type series actually holds two species: the Papagei form as the true ortegai, matching the holotype, and the Pebas form a distinct, possibly undescribed fish now often written Apistogramma cf. ortegai 'Pebas'. On their reading, the type locality near Pebas had been seeded by local collectors moving Papagei fish in from the harder-to-reach middle Ampiyacu, blurring the picture. The question is still open, so a careful account treats the 'Pebas' fish as conspecific only provisionally.
Morphology
This is a small fish even by Apistogramma standards. The type series tops out around 2 in standard length and FishBase lists a maximum of 2 in SL, so a large male is roughly two inches in the body with the fins adding more; females are smaller, commonly an inch to an inch and a half. The body is moderately deep and laterally compressed, with a triangular snout and a low, even dorsal fin whose third-through-sixth membranes — the lappets — draw out into points in adult males, while the soft dorsal and the upper caudal rays can extend into short filaments. Fin counts run to XV–XVI dorsal spines with 6–7 soft rays, three anal spines and 24 vertebrae. What makes the species memorable is colour, and here it earns the word polychromatic — markedly variable even within one wild population. Live males range from iridescent sky-blue to violet over the body, scattered with red flecks on the scales above the lateral band; the cheek is washed pale blue with red markings, the dorsal fin is edged dark and striped in red and blue, the anal fin runs yellow and blue, and the caudal is a warm orange-yellow. Females turn a clean yellow with black markings — the dorsal and pelvic fin fronts inked black and, in spawning condition, a black mid-ventral stripe from the pelvic fins to the vent. Both sexes carry a set of horizontal abdominal stripes between the scale rows, a handy field mark that separates ortegai from several congeners. The describers diagnosed it largely on fine scale counts and tail-spot shape: from Apistogramma eunotus by fewer predorsal (7–8 vs 9–12) and prepelvic (6–8 vs 9–13) scales and the belly stripes, from Apistogramma cruzi by prepelvic scale count, and from Apistogramma aguarico by its short rather than elongate front dorsal lappets. The one pattern that maps onto the disputed forms is the caudal blotch: 'Pebas' fish show a single, roughly horizontal spot at the tail base, while 'Papagei' fish show a taller, vertical double-spot. Frustratingly, the mark is mood-dependent and often invisible, so the two cannot be told apart reliably in a dealer's tank — least of all the near-identical females.
Habitat
As described, Apistogramma ortegai is a narrow-range Peruvian endemic, known with certainty only from small streams feeding the Ampiyacu River around Pebas, in the Loreto lowlands of the upper Amazon basin. (If the 'Pebas' form is eventually shown to be separate, the true range of ortegai may prove to be the middle Ampiyacu rather than the town's environs — another reason to state the distribution cautiously.) The type habitat is a textbook Apistogramma stream: clear, acidic water at pH 6.0 and 79 °F, no more than half a metre deep, running through dense, hard-to-reach forest over a bottom of sand and fallen leaves atop some clay, with no aquatic vegetation to speak of. The fish were collected along the margins, among the leaf litter and root tangle that is the genus's universal cover. In the wider hobby the various ortegai-type forms are tied to soft, tea-stained blackwater tributaries of the Ampiyacu and neighbouring drainages — the shallow, shaded, low-conductivity water typical of this corner of Peru. In the type stream it shared the water with another dwarf cichlid, Apistogramma bitaeniata; the larger cichlids Bujurquina peregrinabunda, Cichlasoma amazonarum and an undetermined Crenicichla; and a characin-and-catfish assemblage that included Corydoras fowleri, several tetras, pencilfish and knifefishes — a community profile that doubles as a blueprint for a faithful biotope aquarium.
Feeding
No dedicated diet study has been published for Apistogramma ortegai, so its feeding ecology is read from its habitat, its anatomy and the well-documented habits of the genus. Like virtually all Apistogramma, it is a micropredator of the leaf litter — a small, substrate-oriented carnivore that picks tiny invertebrates, insect larvae, micro-crustaceans and other meiofauna from among decaying leaves and sand, taking in mouthfuls of fine substrate and sorting the edible from the inert. FishBase places it at a trophic level near 3.3, consistent with an invertebrate feeder rather than a herbivore or detritivore. In its sand-and-leaf-litter stream this puts it in the same guild as its co-occurring congener Apistogramma bitaeniata, the two presumably partitioning the litter layer between them. In the aquarium it feeds readily on small live and frozen foods — newly hatched brine shrimp, microworm, daphnia, frozen bloodworm and cyclops — and most fish will eventually take quality micro-pellets and flake, though wild specimens in particular do best when live and frozen foods make up the bulk of the diet.
Mating
Behaviourally, Apistogramma ortegai is a fairly typical regani-group dwarf cichlid: not a strongly polygamous harem-spawner in the cacatuoides mould, but a looser pairer, where one male may tend one or two females rather than a large harem. Females are the more pugnacious sex toward their own kind — keepers consistently report intense female-on-female aggression as the limiting factor in a group, with each ripe female commandeering and defending a cave or sheltered hollow as her spawning site. Males, in turn, can be rough on females that are not yet ready to breed, so the genus's usual rule applies: give the fish enough floor space, and enough broken-up sightlines, that a harried female can get out of view. Pair formation shows in the females' shift into breeding dress — the yellow ground colour intensifying, the black markings hardening — and in mutual display around a chosen cavity. Because the wild-caught trade has long mixed the blue 'Pebas' and multicoloured 'Papagei' forms, whose females are nearly impossible to tell apart, experienced keepers warn that uncontrolled pairings readily produce hybrids; keeping clean lines means starting from a known, single-locality group rather than a dealer's mixed tank.
Breeding
Like its congeners, Apistogramma ortegai is a cave-spawner with maternal-led brood care. The female selects and cleans a sheltered cavity — under wood or a leaf, in a rock crevice, or in the aquarium a small cave, coconut shell or inverted pot with a chipped entrance — and lays her eggs on its ceiling or wall. Clutches in this group are modest, on the order of a few dozen to perhaps a hundred or so reddish eggs; no precise wild fecundity has been published for ortegai specifically, so that is a genus-typical estimate rather than a measured count. The care follows the standard Apistogramma division of labour: the female tends and defends the eggs and, once they hatch, the wriggler and free-swimming fry, while the male holds the larger surrounding territory. Keepers report the eggs hatching in roughly two to three days, and the female then guarding a tight, mobile shoal of fry, leading them through the leaf litter and shepherding them back to cover at any disturbance. The fry are large enough to take newly hatched brine shrimp and microworm from the outset. Soft, acidic, warm water is the spawning trigger — reports converge on pH around 6 to 6.5 and temperatures in the mid-20s °C — and a generous water change with fresh water a couple of degrees cooler is the classic prompt for a conditioned pair, the same cue that simulates the onset of the rains in the wild. Brood care is comparatively brief; once the female begins to disengage, or starts preparing a new spawn, the fry are best given ample cover or moved on to grow out.
In the aquarium
Occasionally offered in the specialist dwarf-cichlid trade — never common, but sourceable if you look, with the Papagei form turning up fairly regularly through German and Dutch importers — this is a fish for keepers who already know the genus, not for newcomers. The husbandry follows the standard Apistogramma playbook, but the water-chemistry demands leave no room for the unprepared.
Tank: 60 × 15.5 in (about 20 US gal) is a workable minimum for a single pair; 20–25 US gal lets a male hold territory over two females, and a longer 100 × 15.5 in or larger tank opens up a small group while giving you room to break sightlines.
Water: the fish tolerates pH 5.0–6.8 and 75–82 °F, but only colours up and spawns reliably toward the soft, acidic end, with conductivity below roughly 100 µS/cm the target. In hard-water areas, cut RO with a little tap water, or use pure rainwater; neutral or alkaline tap will keep the fish alive but yield neither breeding nor full colour.
Aquascape: a soft sand bottom is essential — these litter-pickers will not settle over gravel — layered with dried leaves (Indian almond, oak, beech), with fine roots or wood for cover, two or three small caves or coconut shells per female, subdued light and gentle filtration; strong flow is neither natural nor appreciated.
Tankmates: small, peaceful, upper-water fish that leave the bottom alone — pencilfish (Nannostomus spp.), ember or rummy-nose tetras, and Corydoras (Corydoras fowleri actually shares the type habitat) — make good dither fish; Otocinclus are fine. Avoid larger cichlids, boisterous barbs and substrate-rooters, and don't crowd two Apistogramma species into a tank too small to give each pair its own territory.
Common mistakes: water that is too hard or too alkaline, too few caves (which turns the females on one another), and carelessly mixing the Papagei and Pebas forms — their near-identical juveniles and females hybridise easily and muddy a line whose wild taxonomy is already contested.
Conservation
Apistogramma ortegai has not been evaluated by the IUCN Red List — it carries no global conservation category — and it is not listed by CITES. That silence partly reflects its youth as a described species and its obscurity, but it also leaves a real data gap, because on the available facts this is exactly the kind of fish that warrants attention: a very narrow-range endemic, known from a single small drainage, that is also collected for the international aquarium trade. A species confined to a handful of forest streams is inherently exposed to localised habitat change — deforestation in its catchment, stream siltation, and the broader degradation of small upper-Amazon tributaries — in a way the basin's widespread generalists are not. None of these pressures has been documented as an active threat to this particular fish, and the upper Ucayali–Amazon lowlands of Loreto remain comparatively intact, but the Amazon basin as a whole faces accelerating stress from deforestation, road-building, mining and altered flood regimes, and a single-stream endemic has little margin if its one home is disturbed. The most immediate hobby-side risk is genetic rather than demographic: because the trade has long conflated ortegai with the 'Pebas' form and other regani-group look-alikes, careless breeding threatens to homogenise or hybridise the distinct wild colour forms in captivity — a loss worth guarding against by keeping single-locality lines pure.