Taxonomy & naming
Apistogramma staecki was described by the German aquarist-ichthyologist Ingo Koslowski in 1985, in a paper in the Bonner zoologische Beiträge (36(1/2): 145–162) that simultaneously introduced its neighbour Apistogramma linkei. Both were named from fresh material collected in the Rio Mamoré system of Bolivia by Horst Linke and Wolfgang Staeck during 1983 fieldwork. The species honours Dr. Wolfgang Staeck, the Berlin biologist, prolific cichlid author, and former president of the Deutsche Cichliden-Gesellschaft, who helped collect the type series. The holotype is a small male, ZFMK 13400, held at the Zoologisches Forschungsinstitut und Museum Alexander Koenig in Bonn; paratypes are distributed across collections in Frankfurt (SMF), São Paulo (MZUSP) and Stockholm (NRM). The type locality is a set of roadside lagoons roughly 6 mi south of the town of Trinidad in the Bolivian Beni, near 14°57'S, 64°51'W.
Apistogramma is the largest genus of South American cichlids, and staecki falls within the eartheater subfamily Geophaginae. Koslowski placed it tentatively near the steindachneri species group, citing shared traits such as the narrow lateral band, the posteroventrally broadening suborbital stripe, and the diagnostic split bars — but he was candid that the species' relationships remained obscure, since its nearest putative relatives live far away in the Rio Negro and the Guianas. For years aquarists applied the name loosely to a similar dwarf from the adjacent Rio Guaporé drainage, traded as 'Apistogramma cf. staecki (Guaporé)' or by the code A193; that fish was formally separated as Apistogramma sororcula by Staeck and Schindler in 2016. Per their description, sororcula differs from true staecki in carrying 10–12 vertical stripes on the caudal fin of adult males (versus fewer in staecki), a lateral band that runs into the caudal fin or caudal spot, and short vertical streaks on the bases of the anterior abdominal scales. The species has no established common name and trades simply under its scientific name.
Morphology
This is a small, moderately elongate Apistogramma. The published size figures are genuinely confusing: FishBase lists a maximum of 1 in standard length (SL) for males and 1.5 in for females, but Koslowski's original account runs the other way — wild specimens were all under about 1 in SL, while aquarium-raised males reached roughly 1.5 in SL (around 1.5 in total length), larger than females at about 1 in SL. The practical expectation for keepers is a fish well under 2 in (2 in) total length, with mature males the larger, more finnage-heavy sex. FishBase's lengths are best treated as a transcription quirk rather than a record of females outgrowing males.
The defining mark is the way bars 5 and 6, and often bar 4, split lengthwise into two narrow vertical stripes — a feature vivid in freshly preserved or aggressively displaying fish but quick to fade in repose. The species lacks the dark flank spot of true steindachneri-group members, carries an unusually high count of gill-cover scales, and shows a narrow postorbital lateral band together with a broad suborbital stripe that displaying males can contract into an ocellus-like spot at the gill-cover edge. Living males are greyish to olive with whitish bellies, blue speckling on the cheeks and gill covers, glittering dorsal-fin colour and short caudal streamers; mature males develop a truncate, squared-off caudal edge with short tips top and bottom (a round tail rules the species out, as moderators on Apistogramma.com note). Females turn bright yellow with bold black markings when in breeding mood. Identification in the trade is notoriously tricky: experienced hobbyists separate true staecki — small caudal spot clearly set off from the lateral band — from the Guaporé fish now called Apistogramma sororcula, in which the band runs continuously to the tail. Many tank specimens sold as 'staecki' cannot be confirmed without locality data.
Habitat
Apistogramma staecki is restricted to the Mamoré and Guaporé river drainages of the upper Amazon basin — the headwaters of the Rio Madeira — spanning lowland Bolivia (Beni) and the adjacent Brazilian states of Rondônia and Mato Grosso. The IUCN estimates its extent of occurrence at about 388,0 mi². This places it among the more southerly Apistogramma; Koslowski noted that the low counts in its lateral-line canals are typical of species at the southern edge of the genus's range.
The natural habitat is shallow and sheltered rather than open river. Staeck recorded the fish in very shallow water just 1 ft deep among dead leaves and submerged wood, or, where the water was deeper (2–3 ft), near the surface among the roots and leaves of floating plants such as water hyacinth (Eichhornia azurea and E. crassipes) and water lettuce (Pistia stratiotes). The water is soft and acidic: at the type locality he measured pH 5.7 and conductivity around 94 µS/cm, and at a nearby brownish, near-stagnant pool a pH near 6 with total hardness under 1°dH and conductivity of just 23 µS/cm. The IUCN account echoes this, describing shallow marginal environments over a substrate of submerged leaf and in macrophyte banks (after ICMBio 2018). FishBase gives the genus-typical warm range of 75–82 °F. These are clear-to-blackwater marginal lagoons and floodplain pools, not the white-water main channels — a margin habitat that matters when assessing what threatens the fish.
Feeding
No dedicated feeding study exists for Apistogramma staecki, so its diet is inferred from its anatomy and from the well-documented habits of the genus — flagged here as inference rather than measurement. FishBase places it at a trophic level of about 3.3, in line with the micropredator role typical of dwarf cichlids: small Apistogramma sift soft substrate and leaf litter for benthic invertebrates — insect larvae, microcrustaceans, worms — and pick at biofilm and detritus. Its subconical, slightly recurved jaw teeth, arranged in two rows, fit this generalist invertebrate-picking habit rather than any specialized diet.
Ecologically it is one of several dwarf cichlids sharing the same shallow leaf-litter and floating-plant margins. Koslowski recorded it alongside Apistogramma linkei and Apistogramma luelingi, and larger cichlids such as Aequidens species, the pike cichlid Crenicichla lepidota, and Cichlasoma boliviense in the same waters. Tellingly, where staecki and linkei co-occurred, staecki was tied to the more acidic water and was absent from the less-acid pools its neighbour tolerated — a hint that water chemistry partitions these look-alike dwarfs across the floodplain. As a small, cryptic, leaf-dwelling fish it is itself prey for larger cichlids, characins, and wading birds, and its reliance on dense cover is as much about predator avoidance as feeding.
Mating
The mating system is the harem polygyny familiar across Apistogramma: males are strictly territorial and, at least under aquarium conditions, frequently hold two or more females, each guarding a separate brood within a single male's larger territory. Pair formation is driven by the female, who claims and defends a cave or sheltered spawning site and signals readiness with the genus's classic transformation to bright yellow marked with jet-black — on the pelvic fins, as a midventral stripe, and along the leading dorsal-fin membranes.
Aggression between rivals and between the sexes is the displaced, ritualized kind typical of dwarf cichlids — lateral displays with the bars and suborbital stripe flared, the lateral band darkening and the suborbital mark drawing down into an eye-spot during confrontation — rather than the heavy combat of larger rift-lake cichlids. Because this species is so seldom kept, most of the detailed behavioural record comes from its close congeners and from Koslowski's limited observations; the broad pattern, however, is consistent across the genus and reliable as a guide.
Breeding
Like most Apistogramma, Apistogramma staecki is a cave-and-substrate spawner with female-biased parental care, not a mouthbrooder. Koslowski reported that pairs deposit their eggs on the underside of plant leaves or on the ceiling of a small cave, in clutches of roughly 50 to 100 eggs — a figure consistent with FishBase's note that eggs are attached to the ceiling of caves and the female tends both eggs and larvae. At 75 °F the eggs hatch after about 72–80 hours, and the fry become free-swimming roughly six days later. The female does the close brood care — guarding, fanning and shepherding the wrigglers — while the male patrols and defends the outer perimeter of the territory rather than tending the clutch directly.
In the aquarium the species behaves like other soft-water Apistogramma: small caves (a flowerpot shard, a half coconut, a film canister) over a fine substrate serve as spawning sites, and very soft, warm, acidic water is what triggers spawning and sustains good fry survival. Hard, alkaline tap water is the usual reason eggs fail to develop or fry are lost in this group. Newly free-swimming fry take microfoods — infusoria and newly hatched brine shrimp — and the female leads and corrals the school for the first weeks. Because true staecki is so rarely in the hobby, documented captive spawnings are few, and much of the practical breeding lore circulating under the name actually pertains to the Guaporé fish now recognized as Apistogramma sororcula.
In the aquarium
Apistogramma staecki is genuinely rare in the hobby — not difficult so much as simply absent from most retail channels. It turns up occasionally at specialist dwarf-cichlid importers and at Apistogramma auctions, but the supply is inconsistent and a buyer should verify locality data before assuming any fish labelled 'staecki' is the real article rather than the Guaporé form now described as Apistogramma sororcula. That caveat aside, the husbandry is well within reach of anyone who has kept soft-water Apistogramma before.
Tank size can be modest: a 60-litre (roughly 24 × 15 × 15 in) aquarium is adequate for a single pair, and 20–25 US gal allows a male with two females without undue crowding. Because the fish comes from water measuring pH 5.7–6.0 and total hardness under 1°dH at the type locality, reproducing those parameters is important not just for conditioning but for egg development and fry survival. Reverse-osmosis or rainwater blended to a conductivity of 50–150 µS/cm, slightly acidified with peat filtration or a handful of catappa leaves, and heated to 75–81 °F is the target. Hard alkaline tap water is the single most common reason this group of Apistogramma fails to spawn or loses fry after hatching — the eggs are sensitive to dissolved minerals at concentrations that most community fish tolerate without complaint. Moderate, gentle filtration (a small internal sponge or a low-flow hang-on) keeps the water clean without the current throughput that would strip the surface mulm these fish use when foraging.
Decoration should recreate the leaf-and-root margin the species inhabits in nature. A sand substrate 1 in deep, a generous scattering of dried catappa or oak leaves, a piece or two of driftwood, and two or three small caves — broken terracotta flowerpots, half coconut shells, or curved slate pieces — provide both spawning sites and the visual breaks that reduce inter-female aggression. Low-light plants (Microsorum, Cryptocoryne, or floating duckweed) help keep the light dim and the fish bold. Dither fish are useful: a small shoal of pencilfish (Nannostomus species), hatchetfish, or similar soft-water characins in the upper column encourages the cichlids to stay visible and relaxed rather than skulking. Avoid large, boisterous tankmates; given the fish's maximum size of roughly 1.5 in TL, anything that can fit the male in its mouth is a genuine threat.
The mating structure is the harem polygyny standard for the genus: one male can hold two females in a 80-litre tank if each female has her own cave cluster with clear visual separation between the territories. Females compete with each other and the weaker individual must have an escape route. A single pair is less demanding to manage and is the sensible starting point for a first breeding attempt. Sexing is straightforward once the fish are close to adult size: males are noticeably larger, carry longer dorsal and caudal finnage, and develop the truncate, squared-off caudal edge with short top-and-bottom extensions described by Koslowski; females remain smaller, rounder-finned, and turn a vivid lemon-yellow with jet-black pelvic-fin markings as they come into spawning condition — a transformation that is both unmistakable and a reliable cue that spawning is imminent.
Spawning follows the cave-spawning pattern documented across Apistogramma: the female deposits 50–100 eggs on the cave ceiling, guards them herself, and at 79 °F the eggs hatch in approximately 72–80 hours; the fry are free-swimming after a further six days and accept newly hatched brine shrimp nauplii and microworm immediately. The male circles the territory but does not participate in direct brood care; he should not be removed unless he is actively harassing the female, as his presence helps suppress intrusions by other fish. Water changes of 10–15% every two to three days with matched soft, warm water help maintain quality without the parameter swings that stress small fry. The species is rated a moderately challenging dwarf cichlid — not because its biology is demanding, but because sourcing confirmed true staecki, conditioning them in the correct water chemistry, and resisting the temptation to keep them in harder water 'just to see' are the steps most often skipped.
Conservation
Apistogramma staecki is assessed by the IUCN as Least Concern (assessed 29 October 2020 by R.G. Frederico, reviewed by T.J. Lyons, and published in the 2025 update). The justification is straightforward: despite very little information on the species, its wide range across the Mamoré and Guaporé drainages — an extent of occurrence near 388,0 mi² — argues against a high extinction risk. The population trend is listed as unknown, and the species is described as apparently common though not abundant. It carries no CITES listing and is harvested as an ornamental fish for national and international trade, but there is no evidence that aquarium collection threatens it; its rarity in shops reflects limited, sporadic importation rather than scarcity in the wild. It also appears in Brazil's national Red Book of threatened fauna (ICMBio 2018) without an elevated-risk category.
The honest reading is that the fish itself looks secure on current evidence, while its habitat is not pressure-free. The IUCN flags habitat loss from agricultural expansion as a plausible but unquantified threat — and the upper Madeira lowlands of Beni, Rondônia, and Mato Grosso sit squarely in an arc of expanding cattle pasture and cropland. As a fish of shallow floodplain lagoons and marginal macrophyte banks, Apistogramma staecki is exactly the kind of species exposed to the draining, clearing, and runoff that accompany that expansion, even where no decline has yet been measured. The broader Neotropical cichlid literature frames the context: Kullander's 2003 checklist in the Reis, Kullander and Ferraris compilation remains the regional baseline. For this species the picture is exactly that — least-concern status, ornamental-trade collection that appears sustainable, and habitat change as the watch-item worth monitoring.