Taxonomy & naming
The Swedish ichthyologist Sven O. Kullander described Apistogramma moae in 1980, in his monographic revision of the genus (Bonner Zoologische Monographien No. 14: 1-152), where it appears on page 61 with figure 9. The epithet is geographic rather than honorific: it points to the Rio Moá, the western-Acre river whose drainage yielded the type material. The holotype (IRSNB 586) is held at the Royal Belgian Institute of Natural Sciences (Institut Royal des Sciences Naturelles de Belgique) in Brussels, and the type locality is precise — the Igarapé São Salvador, an affluent of the Rio Moá near Cruzeiro do Sul, Acre, Brazil, at roughly 7°38'S 72°36'W.
The genus name Apistogramma joins the Greek apistos ("uncertain" or "inconstant") and gramma ("line" or "marking"), a nod to the variable, often incomplete lateral lines that make these dwarf cichlids both charismatic and taxonomically slippery. Within the family Cichlidae, Apistogramma belongs to the South American "eartheater" lineage, the Geophaginae (placed by the Catalog of Fishes under the broader subfamily Cichlinae). Kullander allied Apistogramma moae with Apistogramma eunotus and Apistogramma cruzi, and later workers treat it as a member of the Apistogramma eunotus species complex — a cluster of similar, frequently confused species spread across the western Amazon. Kullander added a brief redescription and illustration in his 1986 monograph on the cichlid fishes of the Amazon River drainage of Peru. Catalog of Fishes, FishBase, GBIF and the IUCN all carry the name as valid and unsynonymized. It should not be confused with the undescribed blackwater form sometimes traded from the same region as Apistogramma sp. "Juruá" / "Cruzeiro", which is a distinct fish.
Morphology
Apistogramma moae is a small fish: the maximum recorded length is 2 in SL (standard length, about 2 in), typical for the genus and modest even among dwarf cichlids. It is not a flashy species by Apistogramma standards. As a member of the eunotus complex it shows the group's general plan — an elongate, laterally compressed body carrying a dark lateral band that runs from behind the eye to the caudal base, a caudal spot, and a series of vertical bars and abdominal markings that strengthen or fade with mood and dominance. Blue-green iridescence can wash the lower body and the bands flanking the primary stripe.
Like other Apistogramma, the species is sexually dimorphic: males grow larger and develop more produced fins and stronger colour, while females stay smaller and turn a vivid yellow when guarding a brood. Reliable in-situ documentation of this particular fish is thin, so the safest description leans on its complex rather than on a long list of unique field marks. Telling it apart from close relatives such as Apistogramma eunotus and Apistogramma cruzi rests on the fine details of the lateral band and barring that Kullander used in the original diagnosis; in the trade it has surfaced under informal names, and confusion with congeners is the rule, not the exception.
Habitat
This is a narrow-range endemic, known only from the upper Rio Juruá basin in Acre, western Brazil — essentially the country's far southwestern frontier with Peru, around Cruzeiro do Sul and the Rio Moá. FishBase records occurrences near Cruzeiro do Sul and treats the species as restricted to the upper Juruá system; the IUCN assessment likewise calls it endemic to Brazil's upper Juruá.
The Juruá itself is one of the Amazon's great whitewater rivers — sediment-laden, turbid, near-neutral in pH and comparatively nutrient-rich, carrying a heavy Andean load downstream. Apistogramma as a genus, though, generally lives not in those muddy main channels but in the quieter side-creeks, igarapés and forest streams that feed them, often over leaf litter and soft sediment — exactly the sort of small left-bank affluent (the Igarapé São Salvador) that the type series came from. FishBase records the species as freshwater and benthopelagic, in water of roughly 70–84 °F (70-84°F); the IUCN classifies its habitat simply as permanent inland rivers, streams and creeks, and in these small forest waters depth is shallow, on the order of 0–7 ft. No in-situ water chemistry has been published for Apistogramma moae, so the pH and hardness figures here are habitat- and genus-typical inferences (soft, gently acidic forest-stream water) rather than recorded data for this fish, and are flagged as such.
Feeding
No diet study has been published for Apistogramma moae specifically, so its trophic ecology is read from the genus, where it is well characterised; this is a flagged genus-typical inference, not a species-level measurement. FishBase places it at a trophic level near 3.3 — a small carnivore. Apistogramma are micropredators: they pick small invertebrates, insect larvae, microcrustaceans such as copepods, and associated detritus and aufwuchs (the film of algae, microbes and tiny animals coating submerged surfaces) from the substrate and leaf litter of slow forest streams.
In that community a fish this size is both predator and prey — a benthic forager working the litter layer, and a mouthful for the larger characins, catfish and cichlids that share the Juruá's tributaries. Its low fishing vulnerability and medium resilience in FishBase reflect what its size implies: a short generation time, modest fecundity, and a population that can rebound quickly where habitat stays intact.
Mating
The genus is overwhelmingly polygynous, and Apistogramma moae, as a eunotus-complex fish, follows the pattern: a dominant male holds a comparatively large territory that overlaps the smaller cave-territories of several females. Members of this complex are often described as "casually polygamous" — where several rival males and females share the water a male may hold to a single female, but given a surplus of females he will maintain and breed with several brood territories inside his own.
Courtship is the female's affair as much as the male's. A ripe female develops conspicuous yellow brooding dress, claims and cleans a confined spawning site, and solicits the territory-holding male. Pair bonds are loose and short-lived, lasting through a single brood cycle rather than persisting like the durable bonds of biparental cichlids. In the tight quarters of an aquarium this social structure makes a brooding female startlingly aggressive toward anything that nears her cave, the male included.
Breeding
Breeding is the one part of Apistogramma moae's biology with a direct species-level record: FishBase reports eggs attached to the ceiling of a cave, tended by the female alone. That is textbook Apistogramma — a cave- or crevice-spawning substrate brooder rather than a mouthbrooder, with maternal, female-only care rather than the biparental model of larger cichlids.
The female does the close work. She selects and cleans a confined site — a rock undercut, a root tangle, a snail shell, or a flowerpot in the tank — lays her clutch on its ceiling, then guards the eggs and, later, the free-swimming fry, advertising her status in the genus's vivid yellow and driving off intruders. The male patrols the wider territory and keeps rivals out. Incubation runs roughly 48-72 hours, with the fry free-swimming after another four to five days depending on temperature. No species-specific clutch count has been published; eunotus-complex congeners typically lay on the order of 40-150 eggs per spawn, the defensible genus-typical figure for a fish this size (flagged as inference, not a measured Apistogramma moae datum). Because the genus is so consistent here and the direct observation for Apistogramma moae matches it, the spawning mode and maternal care are among the few behavioural claims about the species that can be stated plainly rather than hedged.
In the aquarium
Availability is the first hurdle. Apistogramma moae is genuinely uncommon in the hobby — not waiting-list rare, but not a local-fish-store fish either. It reaches keepers through specialty importers and dedicated Apistogramma breeders, usually alongside other western-Amazon dwarfs, and even with fish in hand its identity can be uncertain given the chronic confusion within the eunotus complex. Expect to track it down deliberately.
Tank: 20–30 US gal is a workable minimum for a pair or small harem, provided the footprint is generous rather than tall — these are shallow-water fish that use horizontal space. Fine sand to sift, a deep scatter of dried leaf litter (Indian almond or beech leaves work well), broken terracotta pots, halved coconut shells, small clay caves and driftwood root give both sexes cover; females in particular need several enclosed spawning sites, and the litter grows the microfauna — tiny crustaceans, insect larvae, worms — that mirrors the wild diet. Dim lighting and floating plants encourage bolder behaviour.
Water: aim for the soft, gently acidic character of the upper Juruá igarapés — 75–81 °F (75-81°F) within the FishBase-recorded span of 70–84 °F, pH around 6.0-6.8, and low hardness (1-6 °dH). Mid-range temperature is more accurate to these small Acre forest streams than either extreme; harder or alkaline water is survivable short-term but tends to suppress colour and breeding. The Juruá itself is whitewater, but the creeks feeding it run softer.
Tankmates and social setup: the harem model — one male to two or three females — gives the most natural behaviour and usually better breeding than a single pair, where the male's courtship can turn oppressive after spawning. Provide more caves than females so each brooding female can hold her own site without harassing her rivals. Keep tankmates calm and small, and use a group of active mid-water dither fish (pencilfish, small tetras, similar Amazonian characins) to settle the group; avoid larger cichlids, aggressive barbs, and anything that excavates nests or eats fry. Bottom-sharing corydoras and loaches are fine in principle but can draw a brooding female's aggression over substrate space.
Common mistakes: water too hard or alkaline, too bare a layout with nowhere to hide, tankmates picked for colour over temperament, and a tank too small for a female to establish any real territory. Apistogramma moae is not a forgiving beginner's fish — it suits a keeper with some soft-water dwarf-cichlid or Apistogramma experience, and in a correctly set-up tank is no harder than any other member of the eunotus complex.
Conservation
The IUCN Red List assesses Apistogramma moae as Least Concern, in an assessment carried out by Brazil's Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), assessed 7 November 2018 and published in 2022. The reasoning is straightforward: the species is endemic to the upper Juruá basin in Acre, where it is described as relatively frequent though not abundant, and no significant threats to its population have been identified. The assessment notes ornamental use — the fish is collected and enters both national and international aquarium trade — but at a level the assessors did not flag as a population risk. It is not recorded from any protected area and has no dedicated conservation program, and its population trend is listed as unknown.
That Least Concern label sits inside a larger, more complicated picture for the western Amazon. The Neotropical cichlid fauna of this region is documented chiefly through taxonomic work — Kullander's 1980 revision and 1986 Peru monograph, and the basin-wide accounting in the Check List of the Freshwater Fishes of South and Central America (Kullander 2003), which built on the ecological tradition of authors such as Lowe-McConnell. The upper Juruá whitewater system that Apistogramma moae depends on faces the pressures common to Amazonian frontiers — deforestation, road-building, sedimentation and shifting land use along the Acre headwaters — even where a given fish is not itself in decline. For a narrow-range endemic, that combination is worth watching: the species is genuinely secure today, but its security rests on a small geographic area whose forests and small streams are not themselves guaranteed. The accurate summary is the modest one — Least Concern, lightly collected, locally common, and tied to a single river system whose long-term condition, not the fish, is the real variable.