Taxonomy & naming
Chaetostoma dupouii was described by the Venezuelan ichthyologist Agustín Fernández-Yépez in 1945. The Catalog of Fishes (Eschmeyer, CAS) and FishBase both treat it as a valid species. The type locality has not been confirmed in accessible primary sources, but distributional records centre on the Tuy River basin of northern Venezuela.
A taxonomic caution applies to this species: some non-specialist online sources conflate C. dupouii with Chaetostoma guairense Steindachner, 1881 — an older name from the same Tuy/Guaire/Valencia system. FishBase lists both as valid and separate species, with C. guairense (3 in SL) described from the Guaire River nearly 65 years before C. dupouii. The two share overlapping distributions and similar ecology, and formal morphological comparison in modern literature is sparse. Researchers working with museum material from the Guaire drainage should verify specimen identity against the original descriptions before applying either name.
The genus Chaetostoma belongs to the tribe Chaetostomini within subfamily Hypostominae of Loricariidae. Members of the genus are characterised by strongly plated bodies adapted to clinging to rocks in fast current, and by their specialisation as scrapers of periphyton and algal films from hard substrates.
Morphology
Chaetostoma dupouii reaches a maximum recorded length of 3 in standard length (SL), placing it in the smaller range of the genus. No total-length measurement has been published; an approximate total length of 3.5–4 in can be inferred from standard loricariid body proportions, but this figure is not confirmed in primary sources.
Like all Chaetostoma, the body is strongly depressed and broadly plated — an armoured, flattened profile suited to pressing tightly against submerged rock surfaces in swift current. The ventral mouth is wide and bordered by fleshy lips adapted for scraping biofilm from stone. Genus-level characters include the rows of fine bristle-like odontodes on the sides of the snout (the basis of the genus name) and a robust, spiny pectoral-fin spine useful for bracing in current.
Published morphological detail specific to C. dupouii beyond size is not available in accessible sources. Colouration and pattern data have not been documented in the literature consulted.
Habitat
Chaetostoma dupouii is recorded from the Tuy River basin of northern Venezuela, including the Guaire River subbasin (a major Tuy tributary that drains the Caracas valley) and historically from the Lake Valencia basin to the west. The latter population is now considered extirpated, known only from old museum specimens.
The species inhabits transparent, fast-flowing rivers and streams originating in montane or foothill terrain — habitat typical of the Cordillera de la Costa that backs the Venezuelan Caribbean coast. These headwater streams are characteristically cool (relative to Venezuelan lowland temperatures), clear, and well-oxygenated, with rocky or cobble substrates swept by strong current. No quantitative water-parameter data (temperature, pH, conductivity) have been published for occupied C. dupouii sites.
The lowland Guaire River, once part of the species' range, is now so severely degraded by Caracas's urban growth — carrying heavy loads of industrial, agricultural, and domestic effluent — that it no longer supports this species. Wild populations are presently considered restricted to highland reaches above approximately 1,0 ft elevation, primarily within Macarao National Park and possibly adjacent protected headwater areas.
Feeding
No published feeding study has been conducted on Chaetostoma dupouii specifically. Genus-level biology is, however, well established: Chaetostoma are diatom and algae grazers that scrape periphyton and biofilm from the surfaces of submerged rocks using their broad, papillose lips. The diet is dominated by diatoms, filamentous algae, and the organic material embedded in biofilm (bacteria, fine detritus, fungal hyphae). The wide mouth and strongly keratinised oral disc allow efficient grazing even on tightly adherent epilithic growth in fast current.
In the aquarium, Chaetostoma are generally accepted as algae wafer and biofilm grazers; blanched vegetables (courgette, cucumber) and spirulina-based foods are suitable supplements. Meat-rich foods are not a natural dietary component and should be offered sparingly if at all.
Mating
No published data on mating behaviour in Chaetostoma dupouii are available. By comparison with other Chaetostoma and related hypancistrin genera, males in the breeding season are likely to develop more prominent interopercular odontodes and to exhibit territorial defence of crevice or rocky cave sites in areas of current. Sexual dimorphism in this species has not been documented in the sources consulted.
Breeding
No captive breeding records or published reproductive data have been located for Chaetostoma dupouii. The species has not been reported in the aquarium hobby, and its conservation status (see Conservation) makes collection from wild populations inappropriate. Genus-level inference suggests cave-spawning with some form of male brood guarding, consistent with the loricariid pattern, but this cannot be confirmed for this species specifically.
Data on clutch size, egg morphology, incubation period, and parental behaviour are absent from the literature consulted.
In the aquarium
Chaetostoma dupouii does not appear to be established in the aquarium hobby, and no care reports are on record in the sources consulted. Its rarity in captivity is consistent with its critically limited wild distribution and its Vulnerable status on the IUCN Red List.
By genus-level analogy, Chaetostoma require well-oxygenated, moving water over a rocky substrate with ample biofilm; standard plenum filtration and powerheads creating directional flow are appropriate. Water should be soft to moderately hard and near neutral, reflecting the Andean headwater origin. Robust algae growth on rocks and glass provides a natural foraging surface. Given the species' highland-stream origin, moderately cool water (likely 64–75 °F) may be more appropriate than the warmer conditions used for lowland loricariids, but no published aquarium data confirm optimal temperature for this species.
Conservation
The IUCN Red List assessed Chaetostoma dupouii as Vulnerable (VU) in January 2021 under criterion B1ab(iii), indicating a restricted range with continuing decline in habitat quality. This assessment reflects a severe conservation reality: the Guaire River, which flows through central Caracas and was historically part of the species' range, is among the most polluted rivers in South America. Decades of unregulated urban expansion, industrial discharge, and inadequate wastewater treatment have rendered the lowland Guaire essentially uninhabitable for clean-water loricariids.
C. dupouii is now effectively extirpated from its lowland range. The surviving population is believed to be limited to headwater refugia above approximately 1,0 ft elevation — primarily within Macarao National Park and possibly Henri Pittier National Park — where spring-fed streams remain relatively clean. The Lake Valencia basin population, historically the species' western range, is considered lost (museum records only).
The primary threats are ongoing: water contamination from Caracas's expanding footprint shows no sign of meaningful reversal, and deforestation and erosion in the Cordillera de la Costa foothills continue to degrade catchment quality in the headwater zones. The integrity of Macarao National Park and its riparian corridors is therefore the single most important conservation factor for this species' continued existence.