Taxonomy & naming
Pareiorhaphis mucurina was described by Edson H. L. Pereira, Tiago C. Pessali, and Roberto E. Reis in 2018, in Copeia (volume 106, number 4, pages 632–640), from the Mucuri River basin in Minas Gerais, eastern Brazil. The Catalog of Fishes (Eschmeyer, CAS) recognises it as a valid species (spid 75576).
The genus Pareiorhaphis belongs to the subfamily Neoplecostominae within the Loricariidae; the original description explicitly places the species there. (FishBase's header lists Hypoptopomatinae, a known cataloguing inconsistency for this genus.)
The specific epithet mucurina refers to the type locality, the Mucuri River basin.
Morphology
Pareiorhaphis mucurina reaches at least 4 in standard length (SL) in the examined material, making it one of the larger members of its genus. It has the typical loricariid body plan: a depressed body sheathed in bony scutes, with a ventral suckermouth.
The original description in Copeia provides the full diagnostic combination of characters that separates it from congeners, but no condensed morphological summary beyond overall size and the standard genus features is available in the cached material. Detailed sexual dimorphism is not summarised here; across Pareiorhaphis, mature males typically develop hypertrophied odontodes on the head and pectoral spines, but no species-specific account is published in these sources.
Habitat
The species is restricted to the Mucuri River basin in Minas Gerais, eastern Brazil. It is a freshwater, benthopelagic, tropical species recorded across a depth range of about 0–7 ft.
Field collection notes describe fast-flowing, tea-coloured (blackwater) water over a bedrock bottom, with marginal vegetation preserved along the banks. Specimens were taken at depths of roughly 1–6 ft in stretches 10–52 ft wide. The fish was very abundant at its sites and was mostly hand-caught from among rocks and inside the cracks and crevices of the bedrock. Associated species include Euryochus thysanos, Astyanax aff. fasciatus, and unidentified Characidium and Trichomycterus.
Like other Pareiorhaphis, it is a facultative air-breather.
Feeding
No diet study for Pareiorhaphis mucurina is published in the cached sources. Its bedrock-crevice habitat and ventral suckermouth are consistent with the loricariid habit of grazing biofilm from hard surfaces, but the species' gut contents have not been reported, so no specific dietary claim can be made.
Mating
No data on courtship or mating behaviour has been published for Pareiorhaphis mucurina. No reproductive observations appear in the available sources.
Breeding
No breeding account for Pareiorhaphis mucurina exists in the available literature. Spawning mode, clutch size, and parental care are undocumented for this species, and no inference beyond the general loricariid pattern of male-guarded adhesive eggs would be more than speculation.
In the aquarium
Pareiorhaphis mucurina is not present in the aquarium trade; it carries no L-number and no husbandry experience has been published.
Its wild habitat — fast-flowing, well-oxygenated, tea-coloured water over bedrock with abundant crevices — would suggest a rheophilic setup with strong current, high oxygen, and clean water if it were ever kept, but these are extrapolations from field data rather than tested recommendations.
Conservation
Pareiorhaphis mucurina has not been evaluated by the IUCN Red List (status Not Evaluated), and it is not listed under CITES. FishBase rates its resilience as high, and it was reported as very abundant at its known collection sites.
Its restriction to the single Mucuri River basin means that, although it is locally common, any basin-wide pressures — damming, water abstraction, or pollution in this eastern Brazilian coastal drainage — would bear directly on the species. A formal conservation assessment has not yet been undertaken.