Taxonomy & naming
Neoplecostomus yapo was described by Zawadzki, Pavanelli, and Langeani in 2008 in Zootaxa (No. 1757, p. 40, Fig. 5). No synonyms are recognised. The Catalog of Fishes (Eschmeyer, CAS) treats Neoplecostomus yapo Zawadzki, Pavanelli & Langeani, 2008 as the valid name.
The species belongs to the genus Neoplecostomus, placed here in the subfamily Neoplecostominae — a lineage of small, often torrent-associated suckermouth catfishes of the Atlantic and upper Paraná drainages of southeastern Brazil. (FishBase files Neoplecostomus under Hypoptopomatinae; this atlas follows the Neoplecostominae scheme.) The specific epithet refers to the rio Yapó, the drainage of the type locality.
Morphology
Neoplecostomus yapo is a small loricariid, reaching about 4.5 in (4.5 in) standard length. As in other Neoplecostomus, the body bears the family's armour of bony plates and a ventral suckermouth.
The diagnostic characters separating it from congeners are set out in the original description (Zawadzki et al., 2008). Sexual dimorphism is not detailed in the sources available here, though males in the genus commonly develop odontodes on the pectoral spines and body.
Habitat
The type locality is riacho Fortaleza (at Fazenda Santo Amaro), an affluent of the rio Yapó within the rio Tibagi basin, part of the upper rio Paraná system, at approximately 24°30'34"S 50°24'49"W in Paraná State, Brazil. The species is known from the rio Tibagi basin.
It is a freshwater, benthopelagic, tropical fish. Members of the genus typically occupy clear, flowing upland streams over rocky and gravel substrates, where they cling to the bottom in moderate to swift current; specific in-situ water measurements for N. yapo are not published in the sources consulted.
Feeding
No dietary study specific to Neoplecostomus yapo is available. Neoplecostomus species are benthic grazers that rasp the periphyton — algae, diatoms, and associated invertebrates — from stones in flowing water, and N. yapo is presumed to feed similarly. This is an inference from the genus rather than a documented observation; no captive feeding data exists.
Mating
No information on courtship or mating behaviour has been published for this species.
Breeding
There is no breeding report for Neoplecostomus yapo. Reproduction in the wild and in captivity is undocumented in the sources consulted.
In the aquarium
Neoplecostomus yapo is not established in the ornamental trade, and no husbandry guidance has been published. Any inferences would have to be drawn from the broader genus: small upland-stream catfishes of this type generally require cool to moderately warm, clean, well-oxygenated water with brisk flow and a rocky substrate offering grazing surfaces. These are general expectations for the group, not tested recommendations for this species.
Conservation
The IUCN Red List assessed Neoplecostomus yapo as Least Concern in 2018. As a stream fish of a restricted but apparently stable upper-Paraná drainage, it is not currently considered threatened; nonetheless, small-range upland species can be sensitive to local habitat alteration, water abstraction, and pollution within their single basin.