Taxonomy & naming
Rhinelepis strigosa was described by Achille Valenciennes in 1840 and is recognised as a valid species by the Catalog of Fishes (Eschmeyer, CAS); because the species remains in its original genus, the authority carries no parentheses. Rhinelepis is the type genus of the subfamily Rhinelepinae and the eponym of the Rhinelepis group, the lineage of large rheophilic plecos to which Pogonopoma and related genera also belong.
The nominal species Rhinolepis paraguayensis Borodin, 1927 is regarded as a synonym, based on what proved to be a juvenile of R. strigosa. The phylogenetic placement of the genus within the family was treated by Armbruster (1998) in his study of the Rhinelepis group. FishBase places Rhinelepis strigosa in Loricariidae under Rhinelepinae.
Morphology
Rhinelepis strigosa is a large loricariid, reaching about 19 in in standard length — one of the bigger members of the family and far larger than the dwarf wood-eating plecos common in the aquarium trade. The body bears the characteristic loricariid armour of overlapping bony scutes, and the mouth is a ventral suckermouth.
Beyond overall size, detailed external diagnostic characters are not reproduced here; the redescription and phylogenetic work of Armbruster (1998) is the appropriate reference for morphological detail. No data on sexual dimorphism in this species has been published in the sources reviewed.
Habitat
Rhinelepis strigosa occurs across the Paraná and Uruguay River basins, with a range spanning Brazil, Argentina, Paraguay, and Uruguay. It is a freshwater, demersal, tropical fish.
Like other members of the Rhinelepis group, it is a facultative air-breather, able to supplement gill respiration with aerial gas exchange — an adaptation suited to large, variably oxygenated river systems. Specific water-chemistry measurements from its range are not available in the sources reviewed.
Feeding
Specific dietary data for Rhinelepis strigosa is sparse. As a large benthic loricariid, it would be expected to graze biofilm, algae, and detritus from substrate surfaces, but no quantitative diet study is cited in the sources reviewed, and no firm claim is made here.
Mating
No data on courtship or mating behaviour in Rhinelepis strigosa has been published in the sources reviewed.
Breeding
No data on reproduction, spawning mode, clutch size, or parental care in Rhinelepis strigosa has been published in the sources reviewed. The early life history is touched on only indirectly: the synonym Rhinolepis paraguayensis Borodin, 1927 was based on a juvenile of this species, indicating that young differ enough from adults to have been misidentified as a separate taxon.
In the aquarium
Rhinelepis strigosa is not an aquarium-trade species in any practical sense. At roughly 19 in it is a very large fish, and it is a current-loving river dweller rather than a tank-bred ornamental. There is no established body of home-aquarium husbandry experience to summarise. Any maintenance would demand a very large tank with strong, well-oxygenated flow; for the great majority of keepers it is simply unsuitable, and it is best understood as a wild river fish rather than a hobby subject.
Conservation
The IUCN Red List assessed Rhinelepis strigosa as Least Concern, with the assessment dated 3 December 2020. The Least Concern listing reflects its wide distribution across the large Paraná and Uruguay river systems spanning four countries, with no evidence of a range-wide decline sufficient to warrant a threatened category.
This stands in contrast to its narrowly endemic relative Pogonopoma parahybae, which is confined to a single basin and listed as Vulnerable. The broad range of R. strigosa buffers it against localised pressures, although large South American river basins are not free of threats — damming, flow alteration, and pollution affect the Paraná–Uruguay system as a whole. At present, however, the species is not considered at risk.