Taxonomy & naming
Neoplecostomus altimontanus was described by Uzeda, Paiola, Siqueira-Cesar, Okubo, Marques-Frisoni, Andrade and Langeani in 2024, in Neotropical Ichthyology (volume 22, number 4, article e240021), in a paper presenting two new high-altitude Neoplecostomus from the upper rio Paraná basin of Brazil. The Catalog of Fishes (Eschmeyer, CAS) recognises the name as valid.
The species belongs to the genus Neoplecostomus, which is placed in the subfamily Neoplecostominae of the family Loricariidae. (FishBase lists the species under Hypoptopomatinae, but Neoplecostomus is a Neoplecostominae genus; the subfamily classification followed here reflects that placement.) The genus comprises small armoured catfishes specialised for life in cool, fast-flowing montane streams of southeastern and southern Brazil.
Morphology
Neoplecostomus altimontanus reaches a maximum recorded size of about 3.5 in standard length. The body is elongated with a flattened cross-section, suited to clinging in current, and the fin counts are D 7, A 5.
The original diagnosis lists a suite of distinguishing characters: the exposed area of the first mid-ventral and ventral plates is narrower than the surrounding naked area; azygous (pre-adipose) plates are absent; there are one to two posteronasal plates; an extra canal-bearing plate sits between the supraopercle and the dorsal opening of the preopercular canal; the lateronasal plate is absent; conspicuous dark spots mark the body and fins; slightly hypertrophied odontodes form discontinuous keels on the caudal peduncle; and a well-developed adipose fin spans four to five (usually five) dorsal plates. The species shows sexual dimorphism in dentition — males have more robust but fewer teeth, while females carry 31–42 (modally 35) premaxillary and 31–40 (modally 31) dentary teeth.
Habitat
Neoplecostomus altimontanus is endemic to high-altitude reaches of the upper rio Paraná basin in Brazil, in the region of the Upper Montane Atlantic Forest. It is a freshwater, demersal, tropical species.
The original description reports that it inhabits shallow streams less than 3 ft deep with clear, fast-flowing, low-temperature, well-oxygenated water. The stream banks carry pristine riparian vegetation, with bryophytes, pteridophytes and orchids (Orchidaceae) growing on trees and on exposed stones — a montane setting that is reflected in the species' name.
Feeding
Neoplecostomus species are grazing loricariids of fast, cool streams, rasping biofilm and aufwuchs — algae, micro-organisms and detritus — from rocks and submerged surfaces in the current. No gut-content study specific to N. altimontanus is summarised in the sources consulted, so the feeding profile is inferred from its anatomy and from the ecology of the genus rather than from direct observation of this species.
Mating
No data on the courtship or mating behaviour of Neoplecostomus altimontanus has been published in the sources consulted. The dentition differences between the sexes are documented, but reproductive behaviour itself is undocumented for this species.
Breeding
No reproductive data — spawning mode, clutch size, egg deposition or parental care — has been published for Neoplecostomus altimontanus. No breeding account specific to this species exists in the sources consulted, and the details should not be assumed.
In the aquarium
Neoplecostomus altimontanus is a recently described, range-restricted highland species with no established presence in the ornamental trade and no published husbandry account. Its native environment — shallow, clear, fast, cold and highly oxygenated montane water — would be demanding to replicate, and no species-specific care data is available. No parameters or recommendations can therefore be responsibly stated.
Conservation
Neoplecostomus altimontanus has not been evaluated by the IUCN Red List (status Not Evaluated). As a newly described species restricted to high-altitude streams of the upper rio Paraná in the Upper Montane Atlantic Forest, its population status remains unassessed.
Montane Atlantic Forest streams are sensitive to deforestation, riparian disturbance and climate-driven warming, and a narrowly distributed cold-water specialist could be vulnerable to such pressures — but no formal assessment exists, and no claim about its threat status can be made.