Taxonomy & naming
The Swedish ichthyologist Sven O. Kullander described Apistogramma inconspicua in 1983, in the fourth part of his series on the cichlids of the La Plata basin (Zoologica Scripta 11(4):307, figs. 1–2, dated 1982 but published 1983). The epithet is Latin for "inconspicuous" — a pointed nod to the near-absence of the abdominal stripes and spots that ornament many of its congeners. The genus name reads from Greek as apisto, "uncertain" or "doubtful," plus gramma, a "line" or "mark," together alluding to the variable, often incomplete lateral line that runs through the genus and puzzled its early describers.
The type locality is a small pool of the Río Candelaria (16°00'S, 61°40'W) in Santa Cruz Department, Bolivia, within the Río Guaporé (Iténez) drainage; the holotype is IRSNB 637 at the Royal Belgian Institute of Natural Sciences, with paratypes at IRSNB, the Swedish Museum of Natural History (NRM 16667) and the Museu de Zoologia da Universidade de São Paulo (MZUSP), and further material at the Field Museum (FMNH). Eschmeyer's Catalog of Fishes treats the name as valid and gives the range as the Rio Paraguay and Rio Guaporé drainages of Bolivia and Brazil, and Kullander carried the species forward in his 2003 Checklist of the Freshwater Fishes of South and Central America. One common phrasing is worth correcting: the type locality lies in the Guaporé system, not the Río Mamoré — both are Madeira tributaries, but the Candelaria pool drains to the Guaporé.
Within the genus, Apistogramma inconspicua belongs to the regani lineage and, more precisely, to the commbrae complex — a knot of small, similarly drab species (Apistogramma commbrae, Apistogramma linkei, Apistogramma similis, Apistogramma resticulosa and others) that the longtime Apistogramma authority Mike Wise has described as tending to "merge together at their boundaries." That intergradation, together with a steady trickle of trade fish carrying provisional code numbers, makes the complex one of the harder corners of an already difficult genus. There is no established English common name; in the hobby and the literature the fish travels almost entirely under its scientific name.
Morphology
This is a small fish even by dwarf-cichlid standards. FishBase gives a maximum of about 1.5 in standard length for males and 1.5 in for females — roughly 3 in total length once the tail is counted — while popular references such as Aqualog cite a slightly larger 3 in total. Either way, it ranks among the more diminutive Apistogramma.
The colour is muted: tan to grey-brown with a yellowish cast, brightening in a fired-up male. The diagnostic marks are subtle and read best against the rest of the commbrae complex. A dark blotch sits at the base of the tail, formed where the caudal spot merges with the central part of the last vertical body bar — the "double" caudal mark that flags the complex. The lateral band stops around the sixth body bar rather than running back into that tail spot, and the abdominal markings that stand out in relatives show here only as faint traces, if at all — the very trait the name commemorates. Kullander's account adds two finer points: 15 dorsal spines, against 16 in the closely similar Apistogramma similis, and a distinctive pair of small projections on the rear (posteromedial) teeth of the lower pharyngeal plate. As in most Apistogramma, the sexes differ plainly — males grow larger and carry longer, more produced fins, while females stay smaller and turn a vivid, black-marked yellow when guarding eggs or fry.
Habitat
Apistogramma inconspicua spans two great river systems. In the Amazon basin it holds the upper Guaporé (Iténez) drainage along the Bolivia–Brazil border, a tributary of the Madeira, and it reaches west into the upper Paraguay basin of the Paraná system. The IUCN records it from Bolivia and the Brazilian states of Mato Grosso, Mato Grosso do Sul and Rondônia, with an estimated extent of occurrence near 908,373 mi² (about 350,000 sq mi) — a genuinely wide range for so plain a fish. That a single drab dwarf cichlid straddles the Amazon–Paraguay divide is itself a clue to the region's past: Wise's reconstruction has commbrae-complex ancestors spreading across the western Brazilian highlands through the headwater captures that, in deep time, swapped drainages between the upper Guaporé and the Paraguay.
Its home is the shallow, sluggish margin, not the main channel. Like its close relative Apistogramma commbrae, it favours small streams, floodplain pools and the vegetated edges of larger rivers — among leaf litter, submerged wood and aquatic plants, where the water is rarely more than a metre deep. Recorded in-situ chemistry runs soft and gently acidic to near-neutral: FishBase notes roughly pH 6.5–7.0 and a hardness from about 10 °dH upward, at water temperatures in the tropical 73–82 °F (73–82 °F) band, though the more southerly Paraguay populations see cooler, more seasonal conditions than equatorial Amazonian fishes. These are clearwater and whitewater margins rather than the extreme blackwater some Amazonian Apistogramma demand, and the complex as a whole handles harder, more alkaline water better than most of the genus.
Feeding
Apistogramma inconspicua is a small benthic micropredator. The genus feeds on tiny invertebrates sifted from the substrate and leaf litter — insect larvae, microcrustaceans, worms and the like — and FishBase places this species at an estimated trophic level of about 3.3, the standing of a modest carnivore rather than a top predator. Gut-content studies specific to Apistogramma inconspicua are scant, so this account leans on the better-documented feeding ecology of its close relatives and the genus at large; the picture is of a fish working the floor of shallow, structure-rich water, picking through detritus for small live prey.
In its community it is one of the small players, sharing the vegetated shallows with tetras and other small characins, callichthyid and loricariid catfishes and assorted dwarf cichlids, and serving in turn as forage for larger fishes and water birds. Its modest size, secretive habits and reliance on cover all fit a small mesopredator that spends most of its time hidden among plants and litter.
Mating
Apistogramma inconspicua follows the polygynous, harem template of its genus: a dominant male holds a territory that overlaps the smaller territories of several females, each of which spawns and broods on her own. The male's work is advertisement and boundary defence, while courtship and the close tending of the nest fall to the females, who flush an intense yellow as they ripen and grow sharply territorial around a chosen cave. By Apistogramma standards the fish is relatively peaceful — aggression spikes only around spawning, when a guarding female drives off anything that nears her crevice; the rest of the time it is unassuming and easy to overlook.
Because the species is an uncommon import, usually arriving as wild stock and often muddled with Apistogramma resticulosa or other commbrae-complex fish at the point of sale, much of what keepers report about its courtship is read against the better-documented Apistogramma commbrae. Careful keepers track collection locality and avoid mixing forms, since the complex hybridizes readily and many look-alikes circulate. The honest caveat stands: some of the species-specific detail in the literature is thin, and is filled in by analogy to close relatives.
Breeding
Apistogramma inconspicua is a cave spawner. The female attaches her eggs to the roof of a cave or crevice and does the close tending of clutch and fry, while the male patrols the wider boundary; FishBase notes that he "often takes part" in caring for eggs and larvae, so the division of labour is not absolute — a pattern echoed across the commbrae complex, where care is broadly maternal but the male participates. No clutch count has been published for the species; commbrae-complex females are small fish that typically lay on the order of a few dozen to around a hundred eggs per spawn, and that genus-typical figure is the best available estimate here, flagged as inferred rather than measured.
In the aquarium the requirements mirror those of Apistogramma commbrae. A pair or small harem breeds contentedly in a modest planted tank furnished with soft sand, driftwood, leaf litter and several caves, so each female can claim her own. Soft to moderately hard, slightly acidic to neutral water (pH around 6–7) at 72–82 °F (72–82 °F) suits it, and the southern populations actually benefit from a cooler winter rest to bring pairs into condition. The finer points of spawning triggers and fry development lean on Apistogramma commbrae, in which eggs hatch in roughly 36–72 hours depending on temperature and fry are free-swimming a few days later; the broad outline almost certainly holds here. Start the fry on small live and frozen foods — newly hatched brine shrimp, microworm, Daphnia — and mind the usual dwarf-cichlid rule: these fish are sensitive to accumulated nitrogenous waste and must never go into an immature tank.
In the aquarium
Apistogramma inconspicua is seldom seen in the hobby. It turns up now and then as wild-caught stock from Bolivian or Brazilian exporters, usually unlabelled or under a code number, and even specialist importers sometimes confuse it with Apistogramma commbrae, Apistogramma resticulosa or other complex members. The keepers who seek it out are mostly dwarf-cichlid specialists — it is not a beginner's fish, less for fragility than for its scarcity and the care that species-correct husbandry demands, though it settles into a mature tank without much fuss.
Tank: a single pair, or a harem of one male with two or three females, is comfortable over a footprint of about 60 × 14 in (24 × 14 in) holding roughly 15–20 US gal; a harem does better in a longer tank, around 31.5 in, so each female can stake out her own cave without constant friction. Floor it with soft, fine sand — these fish pick through the bottom all day, and coarse gravel abrades the mucus coat and discourages natural foraging. Dried leaf litter (oak, catappa or beech) over the sand anchors the habitat feel, softens the water slightly as it breaks down and gives micro-cover that visibly lowers stress, while driftwood and tangles of aquatic or floating plants complete the structure. Every female needs her own cave — halved coconut shells with a small entrance, ceramic or terracotta tubes, or small clay pots all serve — and the number of caves should exceed the number of females by one or two, so subordinate fish always have a fallback.
Water: the facts' pH 6.5–7.0 and 73–82 °F (73–82 °F) cover the documented range. A useful quirk of the commbrae complex is its tolerance of moderately hard, near-neutral water, which sets it apart from the soft-water-obligate Apistogramma of the upper Rio Negro or the Peruvian oriente; tap water at 6–10 °dH and neutral pH often works untreated, one of the few practical advantages of keeping this undersupplied fish. Southern Bolivian and upper-Paraguay populations may be tuned to cooler, more seasonal conditions, so a modest winter dip to 68–72 °F (68–72 °F) can help condition pairs. Whatever the target, stable chemistry and pristine water matter more than exact numbers: Apistogramma are disproportionately sensitive to dissolved waste, and a tank that has not fully cycled before the fish go in is the single most common killer.
Tankmates: small, peaceful mid- and upper-water species that leave bottom-dwellers alone are the right company. Pencilfish (Nannostomus spp.), smaller tetras such as green neon or ember, otocinclus and smaller corydoras all make good dither fish, drawing the Apistogramma into the open and absorbing any low-level aggression. Steer clear of larger or boisterous cichlids, aggressive barbs and anything big enough to swallow a 3 in fish. Bottom catfish that would compete for the same crevices — larger loricariids or big doradids — are best kept out of a breeding setup, though small corydoras are usually tolerated. A second Apistogramma species is a bad idea: complex forms hybridize readily, and boundaries already blurry in the field become genuinely compromised in a shared tank.
Sexing and sourcing: adults are easy to tell apart — males run larger with longer dorsal and ventral filaments, while females stay compact and drab until hormones take over and they flush the brilliant black-and-yellow spawning dress. Juveniles are hard to sex reliably, so a group of six to eight grown on together to pair off naturally is the surest route to a colony. Given how uncommon the fish is and how often it is mislabelled, buy stock with documented locality data, keep good records of origin, and avoid mixing collection localities or possible variants even within the complex — the hobby literature here is thin enough that keepers who log honest records add real value to what is known about the group.
Conservation
The IUCN Red List assesses Apistogramma inconspicua as Least Concern, in an assessment dated 30 November 2020 (Frederico; published 2025, reviewed by T.J. Lyons). The reasoning is straightforward: little is known about the species, but its range across the Amazon and Paraguay basins is wide enough that severe, range-wide threats look unlikely. The population trend is listed as unknown — assessors note the fish "does not appear to be very common or abundant" yet document no specific threats. It enters the ornamental trade at local, national and international levels, and Brazil regulates the ornamental collection of native fishes, but there is no evidence that collection pressure endangers it. (An older Cichlid Room Companion profile still flags the species as "not evaluated," which simply predates the 2020 assessment.)
Set in its wider context, Apistogramma inconspicua belongs to the southwestern Amazon's headwaters and the upper Paraguay and Pantanal margins rather than the main Amazon channel, and the pressures it faces are habitat-driven rather than the fishery collapses that dominate African rift-lake conservation. Kullander's contribution to the Checklist of the Freshwater Fishes of South and Central America (2003) catalogues the Neotropical cichlid fauna, and classic surveys such as Lowe-McConnell's work on tropical river fish communities set the ecological backdrop; against it, the real concerns for a small shallow-water specialist are deforestation and agricultural expansion in the Guaporé and upper Paraguay catchments, sedimentation, and the loss of the marginal vegetation it depends on. None of that has been shown to threaten the species today. The honest summary is the unglamorous one: a widespread, little-studied dwarf cichlid that is currently secure, in basins under steadily mounting land-use pressure — a fish to watch rather than worry about.