Taxonomy & naming
Rhinotocinclus pilosus was described by Roberto E. Reis and Pablo Lehmann A. in 2022, as part of the work that erected the genus Rhinotocinclus to accommodate several small-bodied armoured catfishes formerly scattered among Parotocinclus- and Hisonotus-type lineages. It is placed in the subfamily Hypoptopomatinae, the group of miniature suckermouth loricariids, and is treated as valid in the Catalog of Fishes (Eschmeyer, CAS), the authority for valid names.
The specific epithet pilosus is Latin for 'hairy' or 'shaggy', a reference to the species' dermal/odontode texture. Beyond the original description, published material on this species is limited; it has not accumulated a hobbyist L-number, and no widely used common name is in circulation.
Morphology
Rhinotocinclus pilosus is a tiny fish, with a maximum recorded length of about 1 in standard length — placing it among the smallest of the loricariids. As a hypoptopomatine, it carries the lightly armoured, dorsoventrally flattened body and ventral suckermouth typical of the subfamily.
The epithet pilosus points to a hairy or shaggy quality of the integument, consistent with the fine odontode covering seen in related dwarf genera. Detailed meristic and diagnostic counts are given in the original description; no further morphological data are reproduced here to avoid going beyond the published record.
Habitat
The species is recorded from freshwater habitats in Brazil, South America. It is described as a demersal, tropical freshwater fish. Specific water-chemistry measurements (temperature, pH, hardness) and microhabitat details for the type locality are not available in the consulted sources, so no figures are asserted here.
Feeding
No dietary data have been published for Rhinotocinclus pilosus. Hypoptopomatine loricariids are generally aufwuchs grazers, rasping biofilm, algae, and associated micro-organisms from submerged surfaces, but in the absence of stomach-content or field-feeding studies for this species, no specific diet is claimed.
Mating
No data on courtship or mating behaviour have been published for this species.
Breeding
No breeding records or reproductive data are available for Rhinotocinclus pilosus, either from the wild or in captivity.
In the aquarium
Rhinotocinclus pilosus is not an established aquarium species, and no husbandry information is published. As a recently described dwarf hypoptopomatine, it is of taxonomic rather than hobby interest at present.
Conservation
Rhinotocinclus pilosus has not been evaluated by the IUCN Red List (status: Not Evaluated). Its conservation needs, range extent, and population trends remain undocumented, as is common for very recently described small-bodied Neotropical catfishes.