Taxonomy & naming
Ancistrus centrolepis was described by Charles Tate Regan in 1913, based on specimens from the river drainages of northern Colombia. The species was described in its current genus, making the combination Ancistrus centrolepis an original one — the authority is therefore written without parentheses. The Catalog of Fishes (Eschmeyer, CAS) recognises this as a valid species.
The specific epithet centrolepis derives from the Greek kentron (centre, or spine) and lepis (scale), likely alluding to a feature of the median or central scales — though the precise morphological rationale for the name is not elaborated in the original description as accessible through secondary sources. Within Loricariidae the species belongs to subfamily Hypostominae, tribe Ancistrini.
The genus Ancistrus — named from the Greek agkistron, meaning hook, for the hooked interopercular spines — contains well over 70 described species spanning much of tropical South and Central America, with some of the highest diversity found in Andean piedmont rivers. A. centrolepis represents one of a handful of Ancistrus species endemic to the Pacific-slope coastal drainages of Colombia, a region that has received comparatively little ichthyological collecting effort relative to the major Andean trans-continental basins.
The main systematic reference for this species in the checklist literature is Fisch-Muller (2003), who treats the Ancistrinae comprehensively in the Checklist of the Freshwater Fishes of South and Central America.
Morphology
Ancistrus centrolepis reaches a maximum recorded length of 7 in standard length (SL), making it one of the larger members of the genus — considerably bigger than the familiar common bristlenose (A. cf. cirrhosus / A. dolichopterus) typically seen in the aquarium trade, which usually tops out around 4.5–5.5 in SL. At 7 in, A. centrolepis falls at the upper end of Ancistrus body size.
Like all members of the genus, it is a fully armoured loricariid: the body is encased in overlapping bony scutes forming a rigid external skeleton, with rows of lateral plates along the flanks and a flattened ventral surface that allows close contact with the substrate. The sucker-mouth is positioned ventrally, equipped with rows of fine, comb-like teeth suited for rasping biofilm and algae from hard surfaces.
The defining feature of Ancistrus — and the source of the common name bristlenose — is the array of fleshy, branched tentacles projecting from the rostral region and the edges of the snout in males. These tentacles vary in number, length, and degree of branching among species and individuals, and their elaboration in mature males contrasts markedly with the small or absent tentacles of females. In large, mature males the tentacle mass can be visually striking. Females of Ancistrus typically have shorter, marginal tentacles or none at all — a reliable visual sexing criterion for adults.
Specific details of coloration, fin formula, and scute arrangement for A. centrolepis are not well documented in accessible literature, and no image appears on FishBase for this species. Data sparse on diagnostic morphological details beyond size.
Habitat
Ancistrus centrolepis is known from the Atrato, Baudó, and San Juan river basins in northern Colombia — Pacific-slope coastal drainages of the northern Andes. This distributional cluster is distinctly Colombian; it does not extend into Panama as has sometimes been stated in secondary sources, and FishBase explicitly places the range within Colombia.
These rivers occupy a biogeographically distinctive zone. The Atrato flows northward through the Chocó lowlands to the Caribbean (via the Gulf of Urabá), while the Baudó and San Juan are shorter Pacific-slope rivers draining the western face of the Cordillera Occidental. The region is one of the wettest on Earth — parts of the Chocó bioregion receive among the highest annual rainfall recorded anywhere — and the rivers tend to be high-flow, turbid to moderately clear, with substrates ranging from cobble and rock in upland sections to softer sediments in the lowland reaches.
Facultative or obligate air-breathing is recorded for this species on FishBase, which may reflect adaptation to the warm, sometimes oxygen-stressed waters that characterise lowland tropical rivers in this region during dry-season contraction. As with most loricariids, microhabitat is likely associated with hard substrates — rocks, submerged logs, and cobble beds — where biofilm accumulates.
No specific water-parameter measurements (temperature, pH, conductivity) for the known collection localities are available in the literature reviewed. Given the elevation range and latitude of the Chocó drainages, waters are likely warm (72–82 °F) at low elevations, with cooler conditions in piedmont tributaries. Data sparse on confirmed parameters.
Feeding
No species-specific dietary studies have been published for Ancistrus centrolepis. Based on the genus's characteristic morphology — the ventrally placed sucker-mouth, rows of fine scraping teeth, and dorsoventrally flattened body plan — the species is presumed to be a periphyton and biofilm grazer, consuming the algae, diatoms, bacteria, and fine organic matter that accumulate on submerged hard surfaces.
Across Ancistrus, this grazing ecology is supplemented by consumption of plant matter, aquatic invertebrates, and organic detritus. Species from fast-flowing rocky rivers, as the northern Colombian drainages can be in upland sections, tend to specialise in rasping tightly adhered diatom films from cobble surfaces, a food resource that is constantly replenished by current-driven nutrient delivery.
Facultative air-breathing noted for this species suggests it may also exploit warm, slow-moving or stagnant environments, where benthic organic matter and detritus supplement a diet of rock-dwelling algae. The relatively large maximum size (7 in SL) implies substantial daily food intake in the wild.
Mating
No mating behaviour has been observed or reported specifically for Ancistrus centrolepis in the wild or in captivity. The general Ancistrus mating pattern — cave-based, male-territorial, with prominent display of branched snout tentacles — is well documented across the genus and forms the baseline expectation for this species.
In congeners, mature males identify and defend suitable spawning cavities well in advance of the breeding season. The branched tentacles of the male appear to function as both a competitive signal in male-to-male contests and a sensory aid in the confined, often dark spaces where breeding occurs. Males in peak condition — well-fed, with fully developed tentacles — typically attract females more readily and secure preferred cave sites against rivals.
Whether the larger body size of A. centrolepis (up to 7 in SL) influences the scale of cavity requirements or male competition intensity relative to smaller Ancistrus species is not documented.
Breeding
No breeding records for Ancistrus centrolepis in captivity appear in the accessible hobbyist or scientific literature. The species is not commonly available in the aquarium trade, and PlanetCatfish and similar hobbyist resources do not list confirmed breeding accounts.
Based on general Ancistrus biology, the expected breeding mode is cave spawning with paternal brood care. The male selects a cavity, the female deposits adhesive eggs on the interior walls, and the male fans the clutch continuously through incubation, aerating the eggs and removing infertile or fungused individuals. Fry hatch as miniature adults, absorb the yolk sac within the cavity, and begin active grazing shortly after emergence. The male typically guards the brood through the early free-swimming stage.
At the maximum recorded size for this species, a breeding male would require a sizeable cavity compared to smaller Ancistrus — a hollow log section or large cave of appropriate diameter. Specific incubation duration, clutch size, and water triggers for breeding are not documented. Data sparse.
In the aquarium
Ancistrus centrolepis is not an established aquarium fish and is not known to be in regular trade circulation. It has not been assigned an L-number or LDA code by the German aquarium press, which suggests it has rarely if ever appeared in commercial import shipments from Colombia.
Should confirmed specimens become available, the care framework for a large Ancistrus would apply. At up to 7 in SL — approaching 8.5–9.5 in total length — this is a substantial fish by Ancistrus standards, and would require a tank of at least 55 US gal to be kept comfortably long-term, with proportionally large filtration, strong water movement, and ample hard-substrate territory. Multiple flat rocks, slate ledges, and sections of driftwood would replicate the cobble-river habitat and provide both grazing surfaces and shelter.
Water parameters for the Chocó drainages likely fall in a warm tropical range; a working estimate based on regional geography would be 72–82 °F, pH 6.5–7.5, and soft to moderately hard water — but these figures are inferred from regional knowledge, not confirmed measurements from known collection sites.
Diet in captivity would follow the broader Ancistrus template: algae wafers, spirulina discs, blanched vegetables (courgette, cucumber, sweet potato), and periodic protein supplementation. This species is not a recommended beginner fish given its size, relative obscurity, and absence of established care literature. Data sparse; husbandry specifics await confirmed captive experience.
Conservation
The IUCN Red List assessed Ancistrus centrolepis as Least Concern in January 2021. This assessment presumably reflects the species' occurrence across multiple river drainages in northern Colombia without evidence of acute range collapse or population decline.
The Chocó bioregion — encompassing the Atrato, Baudó, and San Juan drainages — is one of the most biodiverse regions on Earth and is recognised as a global biodiversity hotspot. It is also under significant and accelerating pressure from deforestation, illegal gold mining (particularly along the Atrato and its tributaries), agricultural encroachment, and infrastructure development. Gold mining in the Colombian Chocó is a severe and documented threat to river water quality, depositing mercury and sediment loads that can devastate benthic invertebrate and fish communities. The Atrato River has been subject to major environmental litigation in Colombia, with the river declared a subject of rights by the Constitutional Court in 2016 in recognition of its ecological importance and degradation.
For a species like A. centrolepis — dependent on hard-substrate benthic habitat, likely sensitive to elevated sediment and mercury levels — the long-term impacts of mining-related degradation may represent a more serious risk than the 2021 Least Concern assessment implies. More targeted surveys and monitoring would be needed to establish population trends with confidence.