Taxonomy & naming
Corumbataia britskii was formally described by Karina M. Ferreira and Acácio C. Ribeiro in 2007 in Zootaxa (volume 1386, pages 59–68). The type series was collected from two stream sites in Mato Grosso do Sul, Brazil: the holotype (1 in SL) from Córrego Pedra Azul (19°12'15"S 52°43'55"W), a tributary of the Rio Sucuriú in the upper Rio Paraná basin, with paratypes ranging 0.5–1 in SL also drawn from Córrego Fazendinha (19°14'43"S 52°39'11.2"W) in the same tributary system.
The genus Corumbataia was itself named by Britski in 1997 and placed within subfamily Hypoptopomatinae — the group of small, lightly armoured otocinclus-like catfishes that graze periphyton in South American streams. The Catalog of Fishes (Eschmeyer, CAS) recognises Corumbataia britskii as valid with the authorship Ferreira & Ribeiro, 2007.
The authors diagnosed C. britskii from its congeners by a more depressed head profile, a more conspicuous tuft of enlarged odontodes on the supraoccipital tip, and partially enclosed arrector fossae — subtle but consistent osteological characters that require cleared-and-stained material or high-resolution imaging to evaluate.
One point of nomenclatural care: the epithet "britskii" is shared with an unrelated taxon, Parotocinclus britskii Garavello, 1977, also a hypoptopomatine from Brazil. The two are distinct species in separate genera; only the patronymic coincidence links them.
Morphology
Adults of Corumbataia britskii are diminutive even by the standards of the subfamily, with the holotype measuring 1 in SL and the largest paratypes reaching 1 in SL — a maximum standard length of approximately 1 in. The body carries the typical loricariid bony-plate armour and the inferior, disc-like mouth of a committed grazer.
The head is notably depressed — flatter in profile than in congeners — and bears a supraoccipital odontode tuft that is more developed and conspicuous than in related species. The arrector fossae, depressions associated with the pectoral-spine musculature, are partially enclosed, a feature used in the original diagnosis. Like other small hypoptopomatines, the caudal fin is forked and the pectoral spine is stout and interlocking.
Sexual dimorphism has not been described in detail in the literature. In related hypoptopomatines, females are generally broader-bodied when gravid, but specific data for C. britskii are absent from the available cache.
Habitat
Both known collection localities sit within the upper Rio Paraná drainage in the central-western Brazilian state of Mato Grosso do Sul: Córrego Pedra Azul and Córrego Fazendinha, both tributaries of the Rio Sucuriú. The Rio Sucuriú itself is a right-bank tributary of the Rio Paraná, draining a largely agricultural and deforested plateau in Cerrado biome.
FishBase describes the habitat as moderate to fast-current streams in deforested areas, with the fish associated with aquatic macrophytes or marginal riparian vegetation. In the absence of intact gallery forest, such plants may represent the principal structural refuge for small benthic grazers. Specific temperature and pH data have not been recorded at the type localities, but the broader upper Paraná basin typically supports warm, moderately soft to moderately hard freshwater in this region.
The known range encompasses only these two stream sites, and GBIF occurrence records corroborate the restriction to the Córrego Pedra Azul / Rio Sucuriú tributary system. Whether the species persists undiscovered in other Rio Sucuriú tributaries remains unknown.
Feeding
FishBase records the diet of Corumbataia britskii as filamentous blue-green algae (cyanobacteria), chlorophytes (green algae), diatoms, and periphyton including periderm — the biofilm-rich matrix of algae, bacteria, and organic detritus that accumulates on submerged surfaces. This profile is consistent with the broader hypoptopomatine feeding guild: small, disc-mouthed grazers that rasp aufwuchs from macrophyte stems, leaf litter, and hard substrates.
No gut-content study specific to this species has been published beyond the FishBase diet notes, but the ventral mouth morphology and the association with aquatic macrophytes in the field point clearly to a periphyton-grazing lifestyle rather than active predation or detritivory.
Mating
No mating behaviour has been described for Corumbataia britskii in the primary literature or in aquarium accounts. Reproductive biology within the genus Corumbataia is poorly studied. Based on the general biology of small hypoptopomatines, courtship likely involves substrate selection and some degree of male-male competition, but specific observations are lacking. This section will be expanded as data become available.
Breeding
Breeding biology for Corumbataia britskii is undescribed in the literature, and the species has no known aquarium breeding record. Small hypoptopomatines in related genera typically deposit adhesive eggs on sheltered substrates, with some degree of parental attendance, but nothing specific can be stated for this taxon from available sources.
In the aquarium
Corumbataia britskii does not appear in the aquarium hobby in any meaningful way; it is absent from ornamental fish trade databases and from hobbyist forums. Given its restricted wild range, Vulnerable status, and the near-total lack of captive experience, it should be considered unavailable to aquarists.
If specimens were ever maintained, the guiding principle would be to replicate the fast-to-moderate-current, macrophyte-associated habitat of the type locality: a well-oxygenated, lightly decorated tank with steady flow, algae-covered surfaces for grazing, and a diet of periphyton-style foods (algae wafers, biofilm, spirulina). Specific water parameter targets cannot be given from available data.
Conservation
The IUCN Red List assessed Corumbataia britskii as Vulnerable (VU) in November 2018, citing its extremely restricted known distribution — confined to two localities within the Córrego Pedra Azul / Rio Sucuriú tributary system in the upper Rio Paraná basin — and the ongoing threat of habitat degradation driven by deforestation in Mato Grosso do Sul.
The upper Paraná basin has been extensively converted to soy, sugarcane, and cattle pasture over the past half-century. Loss of riparian gallery forest destabilises stream banks, increases sedimentation, raises water temperature, and reduces the aquatic macrophyte cover that C. britskii appears to depend on. The species' single-tributary range means that any localised disturbance — a dam, an agrochemical spill, or the removal of in-stream vegetation — could affect the entire known population.
No targeted conservation measures are in place. The species is not protected under Brazilian federal regulations beyond the general environmental licensing framework. Its Vulnerable status, small body size, and absence from the trade mean there is no commercial incentive for captive propagation. Monitoring of the Rio Sucuriú tributary system and surveys for additional populations represent the most immediate research priorities.